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During the first half of the Holocene (11 000 to 5000 years ago), the Northern Hemisphere experienced a strengthening of the monsoonal regime, with climate reconstructions robustly suggesting a greening of the Sahara region. Palaeoclimate archives also show that this so-called African humid period (AHP) was accompanied by changes in climate conditions at middle to high latitudes. However, inconsistencies still exist in reconstructions of the mid-Holocene (MH) climate at mid-latitudes, and model simulations provide limited support in reducing these discrepancies. In this paper, a set of simulations performed using a climate model are used to investigate the hitherto unexplored impact of Saharan greening on mid-latitude atmospheric circulation during the MH. Numerical simulations show Saharan greening has a year-round impact on the main circulation features in the Northern Hemisphere, especially during boreal summer (when the African monsoon develops). Key findings include a westward shift in the global Walker Circulation, leading to modifications in the North Atlantic jet stream in summer and the North Pacific jet stream in winter. Furthermore, Saharan greening modifies atmospheric synoptic circulation over the North Atlantic, enhancing the effect of orbital forcing on the transition of the North Atlantic Oscillation phase from predominantly positive to negative in winter and summer. Although the prescription of vegetation in the Sahara does not improve the proxy–model agreement, this study provides the first constraint on the influence of Saharan greening on northern mid-latitudes, opening new opportunities for understanding MH climate anomalies in regions such as North America and Eurasia.

Climate change is considered the most pressing environmental challenge of our time, being transport one of the major contributors. Consequently, transport models are required to test different urban mobility policies that can shift travel to more sustainable transport modes (e.g., active modes). This paper focuses on the development of a validated agent-based model (MATSim) applying a novel open-source methodology to generate the main input datasets, easily transferrable to any region in England. Required input datasets (synthetic population and network) are described with a high level of detail, identifying the datasets and tools used to develop them, with special interest in the simulation of cycling routes. A new attribute (quietness) ranking roads for cycling depending on their built-environment characteristics was incorporated into the MATSim bicycle extension. The results obtained in this paper show the baseline transport model of the Tyne and Wear region (England), where discrepancies up to 3.5% in transport mode shares and minimal differences in vehicle counts in urban areas were obtained, and a realistic representation of the routes chosen by the agents using bicycles is obtained. This provides the basis for the development of similar MATSim implementation in other UK regions.

Recent advances in modelling capabilities and data processing combined with vastly improved observation tools and networks have resulted in the expansion of available weather and climate information, from historical observations to seasonal climate forecasts, as well as decadal climate predictions and multi-decadal climate change projections. However, it remains a key challenge to ensure this information reaches the intended climate-sensitive sectors (e.g. water, energy, agriculture, health), and is fit-for-purpose to guarantee the usability of climate information for these downstream users. Climate information can be produced on demand via climate resilience information systems which are existing in various forms. To optimise the efficiency and establish better information exchange between these systems, standardisation is necessary. Here, standards and deployment options are described for how scientific methods can be be deployed in climate resilience information systems, respecting the principles of being findable, accessible, interoperable and reusable. Besides the general description of OGC-API Standards and OGC-API Processes based on existing building blocks, ongoing developments in AI-enhanced services for climate services are described.

Despite the wealth of existing climate forecast data, only a small part is effectively exploited for sectoral applications. A major cause of this is the lack of integrated tools that allow the translation of data into useful and skillful climate information. This barrier is addressed through the development of an R package. Climate Services Toolbox (CSTools) is an easy-to-use toolbox designed and built to assess and improve the quality of climate forecasts for seasonal to multi-annual scales. The package contains process-based, state-of-the-art methods for forecast calibration, bias correction, statistical and stochastic downscaling, optimal forecast combination, and multivariate verification, as well as basic and advanced tools to obtain tailored products. Due to the modular design of the toolbox in individual functions, the users can develop their own post-processing chain of functions, as shown in the use cases presented in this paper, including the analysis of an extreme wind speed event, the generation of seasonal forecasts of snow depth based on the SNOWPACK model, and the post-processing of temperature and precipitation data to be used as input in impact models.

During austral winter, a compact low cloud deck over the South Atlantic contrasts with clear sky over southern Africa, where forest fires triggered by dry conditions emit large amounts of biomass burning aerosols (BBAs) in the free troposphere. Most of the BBA burden crosses the South Atlantic embedded in the tropical easterly flow. However, midlatitude synoptic disturbances can deflect part of the aerosol from the main transport path towards southern extratropics. In this study, the first objective classification of the synoptic variability controlling the spatial distribution of BBA in southern Africa and the South Atlantic during austral winter (August to October) is presented. By analysing atmospheric circulation data from reanalysis products, a six-class weather regime (WR) classification of the region is constructed. The classification reveals that the synoptic variability is composed of four WRs, representing disturbances travelling at midlatitudes, and two WRs accounting for pressure anomalies in the South Atlantic. The WR classification is then successfully used to characterise the aerosol spatial distribution in the region in the period 2003–2017, in both reanalysis products and station data. Results show that the BBA transport towards southern extratropics is controlled by weather regimes associated with midlatitude synoptic disturbances. In particular, depending on the relative position of the pressure anomalies along the midlatitude westerly flow, the BBA transport is deflected from the main tropical route towards southern Africa or the South Atlantic. Moreover, the WRs accounting for midlatitude disturbances show organised transition sequences, which allow one to illustrate the evolution of the BBA northerly transport across the region in the context of a wave pattern. The skill in characterising the BBA transport shown by the WR classification indicates the potential for using it as a diagnostic/predictive tool for the aerosol dynamics, which is a key component for the full understanding and modelling of the complex radiation–aerosol–cloud interactions controlling the atmospheric radiative budget in the region.

In the last 15 years, crustacean fisheries have experienced billions of dollars in economic losses, primarily due to viral diseases caused by such pathogens as white spot syndrome virus (WSSV) in the Pacific white shrimp Litopenaeus vannamei and Asian tiger shrimp Penaeus monodon. To date, no effective measures are available to prevent or control disease outbreaks in these animals, despite their economic importance. Recently, double-stranded RNA-based vaccines have been shown to provide specific and robust protection against WSSV infection in cultured shrimp. However, the limited stability of double-stranded RNA is the most significant hurdle for the field application of these vaccines with respect to delivery within an aquatic system. Polyanhydride nanoparticles have been successfully used for the encapsulation and release of vaccine antigens. We have developed a double-stranded RNA-based nanovaccine for use in shrimp disease control with emphasis on the Pacific white shrimp L. vannamei. Nanoparticles based on copolymers of sebacic acid, 1,6-bis(p-carboxyphenoxy)hexane, and 1,8-bis(p-carboxyphenoxy)-3,6-dioxaoctane exhibited excellent safety profiles, as measured by shrimp survival and histological evaluation. Furthermore, the nanoparticles localized to tissue target replication sites for WSSV and persisted through 28 days postadministration. Finally, the nanovaccine provided ~80% protection in a lethal WSSV challenge model. This study demonstrates the exciting potential of a safe, effective, and field-applicable RNA nanovaccine that can be rationally designed against infectious diseases affecting aquaculture.

Diploid organisms have two copies of each gene, called alleles, that can be separately transcribed. The RNA abundance associated to any particular allele is known as allele-specific expression (ASE). When two alleles have polymorphisms in transcribed regions, ASE can be studied using RNA-seq read count data. ASE has characteristics different from the regular RNA-seq expression: ASE cannot be assessed for every gene, measures of ASE can be biased towards one of the alleles (reference allele), and ASE provides two measures of expression for a single gene for each biological samples with leads to additional complications for single-gene models. We present statistical methods for modeling ASE and detecting genes with differential allelic expression. We propose a hierarchical, overdispersed, count regression model to deal with ASE counts. The model accommodates gene-specific overdispersion, has an internal measure of the reference allele bias, and uses random effects to model the gene-specific regression parameters. Fully Bayesian inference is obtained using the fbseq package that implements a parallel strategy to make the computational times reasonable. Simulation and real data analysis suggest the proposed model is a practical and powerful tool for the study of differential ASE.

There is little knowledge on how the difficulty of forecasting weather may be affected by climate change. Here, the authors find that the atmosphere’s predictability may increase in the future due to warmer oceans.

The study of animal movement is challenging because movement is a process modulated by many factors acting at different spatial and temporal scales. In order to describe and analyse animal movement, several models have been proposed which differ primarily in the temporal conceptualization, namely continuous and discrete time formulations. Naturally, animal movement occurs in continuous time but we tend to observe it at fixed time intervals. To account for the temporal mismatch between observations and movement decisions, we used a state-space model where movement decisions (steps and turns) are made in continuous time. That is, at any time there is a non-zero probability of making a change in movement direction. The movement process is then observed at regular time intervals. As the likelihood function of this state-space model turned out to be intractable yet simulating data is straightforward, we conduct inference using different variations of Approximate Bayesian Computation (ABC). We explore the applicability of this approach as a function of the discrepancy between the temporal scale of the observations and that of the movement process in a simulation study. Simulation results suggest that the model parameters can be recovered if the observation time scale is moderately close to the average time between changes in movement direction. Good estimates were obtained when the scale of observation was up to five times that of the scale of changes in direction. We demonstrate the application of this model to a trajectory of a sheep that was reconstructed in high resolution using information from magnetometer and GPS devices. The state-space model used here allowed us to connect the scales of the observations and movement decisions in an intuitive and easy to interpret way. Our findings underscore the idea that the time scale at which animal movement decisions are made needs to be considered when designing data collection protocols. In principle, ABC methods allow to make inferences about movement processes defined in continuous time but in terms of easily interpreted steps and turns.

The simulation of an industrial boiler in CFD (Computational Fluid Dynamics) is usually done by stages due to the extensive size and the different physical phenomena that occur in different locations of the equipment. In this work, the simulation of an industrial grate boiler is done in three stages, one for the primary air circuit, another one for the secondary air circuit and the final one is the furnace. The combustion of sugarcane bagasse is a complex phenomenon that involves moisture vaporization, devolatilization and char combustion, in order to account for those phenomena, bagasse particles were modeled in a Eulerian-Lagrangian approach. The simulations were performed in commercial software ANSYS FLUENT and the devolatilization model were programmed in C language as a User Defined Function (UDF). When the results of the simulations were compared with experimental data, a satisfactory agreement was observed. Simulations were performed with primary and secondary air inlets modifications in order to optimize the boiler performance, the results of those simulations showed significant improvement in the combustion parameters.

Atmospheric dynamics are described by a set of partial differential equations yielding an infinite-dimensional phase space. However, the actual trajectories followed by the system appear to be constrained to a finite-dimensional phase space, i.e. a strange attractor. The dynamical properties of this attractor are difficult to determine due to the complex nature of atmospheric motions. A first step to simplify the problem is to focus on observables which affect – or are linked to phenomena which affect – human welfare and activities, such as sea-level pressure, 2 m temperature, and precipitation frequency. We make use of recent advances in dynamical systems theory to estimate two instantaneous dynamical properties of the above fields for the Northern Hemisphere: local dimension and persistence. We then use these metrics to characterize the seasonality of the different fields and their interplay. We further analyse the large-scale anomaly patterns corresponding to phase-space extremes – namely time steps at which the fields display extremes in their instantaneous dynamical properties. The analysis is based on the NCEP/NCAR reanalysis data, over the period 1948–2013. The results show that (i) despite the high dimensionality of atmospheric dynamics, the Northern Hemisphere sea-level pressure and temperature fields can on average be described by roughly 20 degrees of freedom; (ii) the precipitation field has a higher dimensionality; and (iii) the seasonal forcing modulates the variability of the dynamical indicators and affects the occurrence of phase-space extremes. We further identify a number of robust correlations between the dynamical properties of the different variables.

On the 30 January 2020, the WHO declared a public health emergency of international concern due to the coronavirus disease 2019 (COVID-19). Social restrictions with different efficiencies were put in place to avoid transmission. Students living in student accommodation constitute an interesting group to test restrictions because they share living places, workplaces and daily routines, which are key factors in the transmission. In this paper, we present a new geospatial agent-based simulation model to explore the transmission of COVID-19 between students living in Newcastle University accommodation and the efficiency of simulated restrictions (e.g., facemask, lockdown, self-isolation). Results showed that facemasks could reduce infection peak by 30% if worn by all students; an early lockdown could keep 65% of the students safe in the best case; self-isolation could keep 86% of the students safe; while the combination of these measures could prevent disease in 95% of students in the best case-scenario. Spatial analyses showed that the most dangerous places were those where many students interact for a long time, such as faculties and accommodation. The developed ABM could help university managers to respond to current and future epidemics and plan effective responses to keep safe as many students as possible.

The Mediterranean region is an area where prediction at different timescales (subseasonal to decadal or even longer) is challenging. In order to help constrain future projections, the study of past climate is crucial. By improving our knowledge about the past and current climate, our confidence in understanding the future climate will be improved. In this Special Issue, information about long-term climate variability in the Mediterranean region is assessed, including in particular historical climatology and model applications to assess past climate variability, present climate evolution, and future climate projections. The seven articles included in this Special Issue explore observations, proxies, re-analyses, and models for assessing the main characteristics, processes, and variability of the Mediterranean climate. The temporal range of these articles not only covers a wide period going from the present day to as far back as 25 centuries into the past but also covers projections of future climate over the next century.

Summer hot temperatures have many impacts on health, economy (agriculture, energy, and transports), and ecosystems. In Western Europe, the recent summers of 2003 and 2015 were exceptionally warm. Many studies have shown that the genesis of the major heat events of the last decades was linked to anticyclonic atmospheric circulation and to spring precipitation deficit in Southern Europe. Such results were obtained for the second part of the 20th century and projections into the 21st century. In this paper, we challenge this vision by investigating the earlier part of the 20th century from an ensemble of 20CR reanalyses. We propose an innovative description of Western-European heat events applying the dynamical system theory. We argue that the atmospheric circulation patterns leading to the most intense heat events have changed during the last century. We also show that the increasing temperature trend during major heatwaves is encountered during episodes of Scandinavian Blocking, while other circulation patterns do not yield temperature trends during extremes.

We analyse and quantify the recurrences of European temperature extremes using 32 historical simulations (1900–1999) of the fifth Coupled Model Intercomparison Project (CMIP5) and 8 historical simulations (1971–2005) from the EUROCORDEX experiment. We compare the former simulations to the 20th Century Reanalysis (20CRv2c) dataset to compute recurrence spectra of temperature in Europe. We find that, (1) the spectra obtained by the model ensemble mean are generally consistent with those of 20CR; (2) spectra biases have a strong regional dependence; (3) the resolution does not change the order of magnitude of spectral biases between models and reanalysis, (4) the spread in recurrence biases is larger for cold extremes. Our analysis of biases provides a new way of selecting a subset of the CMIP5 ensemble to obtain an optimal estimate of temperature recurrences for a range of time-scales.

In the fluid catalytic cracking (FCC) process, the riser is the most important equipment where the reaction taken place. In the riser operation, the feedstock is fed through injectors and mixed with catalyst and steam. A good design and localization of the injectors to ensure rapid evaporation of the feedstock and a good contact of the droplets with the catalyst is important to improve the process efficiency due to a better reagent distribution which ensures a good feedstock conversion and product yields. Hydrodynamic modelling, heat transfer and cracking reactions were studied in this paper using Computational Fluid Dynamic (CFD) in order to evaluate the effect of nozzles design and configuration on the homogeneity of the gas-solid distribution. A 3D model was solved with the Eulerian – Eulerian approach using ANSYS/CFX version 14.0 as calculation tool. The simulation results showed that the distribution of gas-solid depends significantly on the configuration of the feedstock injectors.

The fluid catalytic cracking (FCC) process is at the heart of a modern refinery oriented toward maximum commercial (gasoline and diesel) production. In order to describe the large number of components present in heavy distillates and the kinetic models that are able to predict the profiles of heavy and light chemical fractions in industrial risers, the 12 lump approaches has been used. Gas acceleration inside the reactor due to molar expansion and catalyst deactivation were considered by simulating unsteady state cases over a time long enough to show that the variables had a cyclic behavior. The tracer particle was instantaneously injected following the tracer technique, to get an estimation of the residence time. The governing equations were solved numerically by finite volume method with a commercial CFD code, CFX version 14.0. Appropriate functions were implemented in the model by considering the heterogeneous kinetics, catalyst deactivation and function tracer. The simulation results were validated against the experimental results. This work was carried out in order to evaluate the predictions of product yields and to estimate the residence time distribution in industrial reactors.

The fluid catalytic cracking (FCC) process is at the heart of a modern refinery oriented toward maximum gasoline and diesel production. Within the entire refinery process, this process offers the greatest potential for increasing profitability; even a small improvement in the gasoline yield it implies a substantial economical profit when dealing with a production of millions of barrels of gasoline a day. There are several articles published in the last two decades focusing the attention on 2-D and 3-D computational fluid dynamic models of the industrial riser of a circulating fluidized bed. Nevertheless, there are few research works published in the literature that include studies on how the localization of feedstock along the riser affects the yield products. A 3D hydrodynamic model coupled with a 12 lump kinetic model is presented in this work. Four different injection points in an FCC industrial riser were considered in order to evaluate the hydrodynamic behavior and their effect in the gas oil conversion and products yield. The equations were solved numerically by finite volume method using the Eulerian-Eulerian approach and a commercial CFD code, CFX version 14.0. Appropriate functions were implemented in the model via user defined functions considering the heterogeneous kinetics and catalyst deactivation. The results from the model were validated against the experimental industrial results and it was found that the conversion of gas oil and the production yield significantly change with the feedstock localization.

Circulating fluidized beds (CFBs) have applications in many industrial processes like fluid catalytic cracking, coal gasification, coal combustion, biomass gasification and chemical looping. Consequently, the process have been studied intensively for many researchers seeking to understand the complex gas-solid flow encountered in circulating fluidized beds. In this sense, the Computational Fluid Dynamics (CFD) tools are very useful to study gas-solid flows, but this approach directly depends on the correct choice of the mathematical models. There are many numerical studies on CFBs at low solids fluxes and only a few studies for high solids flux, which is very common in many applications, therefore, this regime was chosen to conduct the simulations in this work. The results were compared with experimental data on a riser with an internal diameter of 76 mm and a height of 10 m. Radial and axial profiles were computed using a two-phase 3-D computational fluid dynamics model, with four different correlations for the drag between the phases, Gidaspow, Syamlal-O’Brien, and other two models that account for particle clusters, the energy-minimization multi-scale (EMMS) and the Four-Zone model. The results indicates that all the correlations predicts the solids concentration, found experimentally, in the dilute and developed flow regions but, in the region of highest solids concentration, especially at the level close to the inlet, the Gidaspow and Syamlal-O’Brien correlations not properly represented the solids concentration. The EMMS and Four-Zone models improved the results on these regions showing the influence of these models especially at the bottom of the riser, where the solids concentration is higher.

Feedstock conversion and yield products are studied through a 3D model simulating the main reactor of the fluid catalytic cracking (FCC) process. Computational fluid dynamic (CFD) is used with Eulerian-Eulerian approach to predict the fluid catalytic cracking behavior. The model considers 12 lumps with catalyst deactivation by coke and poisoning by alkaline nitrides and polycyclic aromatic adsorption to estimate the kinetic behavior which, starting from a given feedstock, produces several cracking products. Different feedstock compositions are considered. The model is compared with sampling data at industrial operation conditions. The simulation model is able to represent accurately the products behavior for the different operating conditions considered. All the conditions considered were solved using a solver ANSYS CFX 14.0. The different operation process variables and hydrodynamic effects of the industrial riser of a fluid catalytic cracking (FCC) are evaluated. Predictions from the model are shown and comparison with experimental conversion and yields products are presented; recommendations are drawn to establish the conditions to obtain higher product yields in the industrial process.

Se realiza un estudio en 7 consultorios médicos del Policlínico Docente "Tomás Romay", del municipio Artemisa, para analizar algunos aspectos epidemiológicos de la úlcera péptica en pacientes dispensarizados en las historias clínicas familiares por esta enfermedad. Se encontró una prevalencia del 1%. La úlcera gástrica fue más frecuente después de los 40 años de edad. Se investiga, además, su relación con los hábitos tóxicos, el régimen de alimentación previo, el grupo sanguíneo, los antecedentes familiares y el estrés. Las manifestaciones clínicas más frecuentes fueron: el dolor, la acidez y la pirosisA study was conducted in 7 medical offices from "Tomás Romay" Teaching Polyclin cs, Artemisa municipality in order to analyze certain epidemiologic aspects of peptic ulcer in dispenzarized patients. A prevalence of 1 % was observed. Gastric ulcer was found to be more frequent after 40 years of age. The relation of peptic ulcer to toxic habits, previous feeding practices, blood group, familial history and stress, is also under research. The most frequent clinical manifestations were: pain, acidity, and pyrosis.

Se realizó un estudio prospectivo en 94 pacientes asmáticos atendidos en el consultorio médico de la familia No. 43 perteneciente al Policlínico Docente "Antonio Maceo" del municipio Cerro de Ciudad de La Habana. Durante un año (junio de 1991 a mayo de 1992) relacionamos las eventualidades diarias del estado de salud de estos pacientes con la densidad de oxígeno en el aire según la fórmula de Gotzek (9/m³) se obtuvieron los datos en el Departamento de Climatología del Instituto de Meteorología de la Academia de Ciencias de Cuba. El análisis estadístico se realizó con el uso del entrecruzamiento de variable, regresión múltiple, método de paso a paso del paquete estadístico SPSS/PC Plus. Se realizó matriz de correlación lineal paramétrica. Se obtuvo correlación significativa directa.

Although the genotype-phenotype map plays a central role both in Quantitative and Evolutionary Genetics, the formalization of a completely general and satisfactory model of genetic effects, particularly accounting for epistasis, remains a theoretical challenge. Here, we use a two-locus genetic system in simulated populations with epistasis to show the convenience of using a recently developed model, NOIA, to perform estimates of genetic effects and the decomposition of the genetic variance that are orthogonal even under deviations from the Hardy-Weinberg proportions. We develop the theory for how to use this model in interval mapping of quantitative trait loci using Halley-Knott regressions, and we analyze a real data set to illustrate the advantage of using this approach in practice. In this example, we show that departures from the Hardy-Weinberg proportions that are expected by sampling alone substantially alter the orthogonal estimates of genetic effects when other statistical models, like F2 or G2A, are used instead of NOIA. Finally, for the first time from real data, we provide estimates of functional genetic effects as sets of effects of natural allele substitutions in a particular genotype, which enriches the debate on the interpretation of genetic effects as implemented both in functional and in statistical models. We also discuss further implementations leading to a completely general genotype-phenotype map.

Resumen: En los últimos años se ha producido un importante incremento del número de personas que viaja a todos los puntos del mundo, incluyendo países exóticos. Así alrededor de 10 millones de personas, desde inmigrantes y turistas hasta diplomáticos y empresarios, se mueven anualmente entre Europa y los llamados países del tercer mundo. Debido a estos movimientos de población ha aumentado el riesgo de padecer no sólo enfermedades de distribución cosmopolita como Tuberculosis, Hepatitis, SIDA, ETS, etc si no también enfermedades tropicales y otras derivadas de los cambios de clima y alimentación. Sin duda la cifra más elevada de personas que acude a los Centros de salud o bien a los Centros de Vacunación Internacional dependientes de los Servicios de Sanidad Exterior antes de emprender un viaje son los turistas, pero hay que tener en cuenta que bajo la definición de turista se encuentran viajeros cuyos riesgos son muy dispares, ya que hay diferencias sustanciales entre los viajes organizados que siguen rutas turísticas preestablecidas y aquellos viajeros que se adentran en zonas recónditas o aquellos que practican el turismo deportivo: trekking, escalada, rafting, etc. Por ello el objetivo principal de este trabajo es aportar una serie de conocimientos básicos en relación a los viajes turísticos, vacunaciones, y sanidad exterior. Abstract: In the last few years it is taking place an important increment of the number of people who travel all over the world, including exotic countries. In this way, about 10 million people, including both immigrants and tourist and diplomatic and businessmen, move annually among Europe and the so-called countries of the third world. Due to these population´s movements it has been increased the risk of suffering not only from diseases of cosmopolitan distribution like Tuberculosis, Hepatitis, AIDS, ETS, etc but also tropical diseases and another ones derived from the changes of climate and nutrition. Undoubtedly, the majority of people who goes to the Health Centre or to the International vaccination Centres dependent on the foreign Health Services before beginning a journey are tourists, but it is necessary to consider than under the definition of tourist are travellers with different risks, because there are substantial differences among the package tours that follow already-established tourist routes and those travellers who go into recondite zones or those who practice the sports tourism: Trekking, climbing, rafting, etc. Hence the main objective of this article is to contribute some basic knowledge in relation to tourist journeys, vaccinations, and foreign health. Centro de Trabajo: Hospital Central de Asturias y Hospital Princesa Sofía (León) Fecha del Trabajo: 01/06/2004 Palabra Clave: Vacunas, viajes, Sanidad Exterior Key Words: Vaccines, journeys, Foreign Heatlh.

Se realiza una revisión de la literatura médica al respecto y se señalan las pautas actuales del tratamiento broncodilatador intercrítico del paciente asmático, con el objetivo de facilitar al personal de atención ambulatoria los elementos necesarios en la atención de nuestros pacientes.

Abstract: Background: A higher incidence of inflammatory bowel disease (IBD) in industrialized areas has been previously reported, but the effect of emigrating to western industrialized countries for a period of time and returning to the country of origin is unknown. Aim of the study was to evaluate the effect of emigrating to another country and returning to the place of origin on the risk of IBD. Methods: A prospective case-control study was performed. Inclusion criteria were all patients >18years diagnosed with Crohn''s disease (CD) or ulcerative colitis (UC) in the last 10years. Healthy, unrelated controls, matched by sex, age and smoking habits, with no family history of IBD were included. All patients and controls were interviewed and emigration was defined as living for at least one year in another country. Results: 242 consecutive patients with IBD (105 CD and 137 UC) and 242 controls were included. Patients who had previously emigrated developed more frequently IBD than controls (OR 1.93, 95%CI 1.19–3.15, p <0.01). Patients who emigrated to European countries developed more frequently IBD than controls (OR 1.91, 95%CI 1.07–3.47, p =0.02), but not those who had emigrated to Latin America (OR 1.48, 95%CI 0.67–3.27, p =0.32). Emigration plays a significant role in the development of UC (OR 2.24, 95%CI:1.29–3.88, p <0.01), but not in CD (OR 1.56, 95%IC:0.83–2.92, p =0.15). Conclusions: People who emigrate to westernised countries have a higher risk for developing IBD, especially UC. Environmental factors related with industrialization seem to play an important role in the pathogenesis of these diseases. [Copyright &y& Elsevier]