A conceptual approach to tourism typology. A classification proposal

Durante las últimas décadas el turismo se ha convertido en una actividad en la que la oferta y la demanda han aumentado su diversidad. Esta es una de las razones que explican la multiplicación de los tipos de turismo (turismo de golf, birdwatching, etc.). Junto a estas tipologías se presentan otras más difíciles de conceptualizar. Para evitar confusiones resulta necesario contar con unas pautas claras de clasificación de tipos de turismo. El presente artí-culo de investigación aborda una propuesta de clasificación de tipologías a partir de una serie de criterios básicos previamente definidos.During these past decades, tourist supply and demand have both diversified. This is one major reason why different types of tourism have multiplied (golf tourism, birdwatching, etc.) Along with these typologies, there are others that are more difficult to conceptualise. To avoid this confusion, clear guidelines are necessary in order to classify types of tourism. The present article sets out a proposal to classify tourist typologies or modalities based on a series of previously defined basic criteria

<i>meta</i>-Selective olefination of fluoroarenes with alkynes using CO₂ as a traceless directing group.

From Europe PMC via Jisc Publications RouterHistory: ppub 2020-03-01, epub 2020-03-31Publication status: PublishedFunder: Engineering and Physical Sciences Research Council; Grant(s): EP/L014017/2Over the last few decades C-H olefination has received significant interest, due to the importance and usefulness of aryl olefins both as synthetic targets and intermediates. While a wide range of ortho-olefination protocols have been developed, only a small number of meta-olefinations are currently available. Importantly, the most common approach to meta-olefination, using a large meta-directing template, is not suitable for substrates such as fluorobenzenes, which cannot be derivatised. We report that the meta-selective olefination of fluoroarenes can be achieved via the use of CO2 as a traceless directing group, which can be easily installed and removed in a one-pot process. Furthermore, this approach avoids the use of stoichiometric Ag(i)-salts, commonly used in C-H olefinations, and affords complete meta- over ortho/para-regioselectivity

Influencia de la concentración de nutrientes y la herviboría sobre la estructura y la función de una comunidad algal

Un mismo conjunto de algas puede generar diferentes ensamblados finales estables en función del ambiente (lago, laguna, etc.) en que se desarrollen. En este trabajo se pretende averiguar qué mecanismos están afectando simultáneamente al conjunto de especies para que se produzca una selección de ellas apropiada a cada ambiente acuático, y cómo la variabilidad de la respuesta se ve reflejada en la estructura y función de la comunidad (biomasa total, fotosíntesis y respiración). Se ha ensayado la formación de una comunidad algal a partir de la disposición simultánea de 8 especies de algas cosmopolitas de agua dulce de morfología bien distinta (Cosmarium contractum, Cryptomonas ovata, Euglena gracilis, Limnothrix redekei, Monoraphidium contortum, Pediastrum tetras, Planktothrix agardhii y Scenedesmus acutus) en distintos tipos de medio de cultivo. Los tratamientos han sido cuatro: mayor y menor concentración de nutrientes (N y P) y presencia o no de Daphnia magna, Keratella cochlearis y Brachionus calicyflorus. Se han ensayado, además, sistemas de competencia entre algas y se ha averiguado la viabilidad de estas especies como inóculos tras un período de senescencia. La presencia de herbívoros (depredación) y la concentración de nutrientes (competencia), son los mecanismos que aislada o sin enérgicamente afectan al ensamblado de microalgas determinando diferentes estados alternativos desde un mismo conjunto de microalgas. Pero el efecto de estos mecanismos es a su vez diferente en función de las propiedades de las microalgas implicadas como son su tamaño, su tasa de crecimiento y la viabilidad de cada especie como inóculo. La presencia de herbívoros y la oligotrofia reducen la biomasa de productores primarios pero aumentan la diversidad relajando la competencia y aumentando la incertidumbre sobre el final alcanzado. Se demuestra además que las variaciones en la estructura de la comunidad se reflejan directamente en su función, afectando en última instancia a la producción primaria y la respiración.The same pool of algae can generate different final stable assemblages depending on the environment (lake, lagoon, etc.) where they develop. In this work we attempt to ascertain the mechanisms that simultaneously affect the species to appropriately select them for each aquatic environment, and how the variability in the response is reflected in the community structure and function (total biomass, photosynthesis and respiration). An algal community has been formed assembling 8 species of freshwater cosmopolite algae which have quite different morphologies (Cosmarium contractum, Cryptomonas ovata, Euglena gracilis, Limnothrix redekei, Monoraphidium contortum, Pediastrum tetras, Planktothrix agardhii and Scenedesmus acutus) using several kinds of culture media. The treatments were four: low and high nutrient concentrations (N and P) and presence and absence of Daphnia magna, Keratella cochlearis, and Brachionus calicyflorus. The competition between pairs of algae has been studied and also the viability of the species as inoculum after a senescence period. The presence of herbivores (predation) and the nutrient concentration (competition) are the mechanisms that by themselves or sinergically affect the microalgae assemblages originating different alternative states from the same pool of species. But the effect of these mechanisms is different depending on the algal properties such as size, growth rate, and viability as inoculum. The presence of herbivores and the oligotrophic conditions reduce the primary producers' biomass but increase diversity due to relaxation of competition and increase the uncertainty of final states. It is also shown that the variations in the community structure are directly reflected on the function, affecting primary production and respiration

Directions of high cycle fatigue cracks emanating from circular notches studied by optical profilometry

Current models for predicting the fatigue endurance of notched solids use the stresses along a straight line, beginning at the notch root, as a simplification of the real crack propagation path. In this work, the experimental crack paths for hollow notched samples were analysed through different microscopy techniques, with the objective of establishing high cycle fatigue crack growth directions in a mild steel. Fully reversed tension–compression fatigue tests of thin-walled tube specimens with a passing-through hole were carried out. The crack paths observed in the outer cylindrical surface were studied in each case, with special attention to the crack initiation point and the crack direction along the first grains. Moreover, the analysis of the fracture surfaces allowed the same analysis to be performed to determine the internal crack paths. It was observed that the crack initiation point was close to the maximum principal stress point at the hole contour as obtained from linear elastic finite element analysis, and the crack direction in its initiation was generally close to Mode I direction, contrary to the conventionally accepted 45 crack growth direction.The authors would like to thank the European Union, the Spanish Government and the Junta de Andalucía for its financial support through grantsDPI2017-84788-PandPID2020-117407GB-I00(FEDER/Ministerio de Ciencia e Innovación - Agencia Estatal de Investigación) and P18-FR- 4306 (‘‘Fondo Europeo de Desarrollo Regional (FEDER) y Consejería de Economía, Conocimiento, Empresas y Universidad de la Junta de Andalucía, dentro del Programa Operativo FEDER 2014-2020’’). N.O. Larrosa would also like to thank the UK Engineering and Physical Sciences Research Council (EPSRC) for its financial support through grant number EP/S012362/1

Relación entre la perimetría automatizada convencional y la topografía papilar realizada con el tomógrafo Heidelberg

espanolObjetivo: Determinar las correlaciones entre los parametros de la cabeza del nervio optico (CNO) obtenidos mediante el laser confocal de barrido (HRT), y los resultados de la perimetria automatizada convencional (PA) en sujetos normales, hipertensos oculares (HTO), sospechosos de glaucoma y glaucomatosos. Metodos: Cuatrocientos veintitres ojos fueron incluidos en el estudio y clasificados segun la presion intraocular basal, morfologia papilar y los resultados de la PA en 4 grupos: 87 normales, 192 hipertensos oculares, 70 sospechosos de glaucoma y 74 glaucomatosos. En los diferentes grupos diagnosticos, se calcularon los coeficientes de correlacion de Pearson entre los parametros de la CNO y la desviacion media (DM), la desviacion estandar de la media (DSM), el numero de puntos alterados en cada cuadrante del campo visual (superior-nasal, inferior-nasal, superior-temporal e inferior-temporal), el numero de puntos alterados segun los niveles de probabilidad y los valores umbral en cada punto de la PA. Resultados: En el grupo normal y de hipertensos oculares, se encontraron pocas correlaciones debiles entre los parametros del HRT y los resultados de la PA. La fuerza y el numero de correlaciones significativas aumentaron en el grupo de sospechosos de glaucoma. En el grupo de glaucomas, las correlaciones fueron mas fuertes, especialmente entre los cocientes excavacion/disco y anillo/disco con la DM (r=0,479) y entre el area de anillo con la DSM (r=0,444). Conclusiones: Se encontraron correlaciones debiles o moderadas entre algunos parametros de la CNO medidos con el HRT y los resultados de la PA, en el grupo de glaucomas. EnglishPurpose: To determine the correlations between optic nerve head (ONH) parameters measured with the Heidelberg Retina Tomograph (HRT), and the main outcomes of standard automated perimetry (SAP) in normal, ocular hypertensive, glaucoma suspects and glaucomatous subjects. Methods: Four hundred and twenty-three patients were enrolled in the study and classified into four groups depending on baseline intraocular pressure, optic nerve head morphology, and SAP results: 87 normal eyes, 192 ocular hypertensive eyes, 70 glaucoma suspects and 74 glaucomatous eyes. In the different diagnostic groups, Pearson's correlation coefficients were calculated between ONH parameters and mean deviation, pattern standard deviation (PSD), number of altered points in each quadrant of the visual field (superior-nasal, inferior-nasal, superior-temporal and inferior-temporal), number of points altered at different probability levels, and threshold values at each point of SAP. Results: In the normal and ocular hypertensive groups, only a few weak correlations were found between HRT and SAP parameters. The strength and number of significant correlations increased in the suspected glaucoma group. The glaucoma group had the strongest correlations, particularly between cup/disc ratio and rim/disc ratio with MD (r=0.479) and between rim area and PSD (r=0.444). Conclusions: Weak to moderate correlations were found between some ONH parameters obtained with the HRT and SAP results in the glaucoma grou

Caustic Ingestion in Children

Caustic ingestion (CI) is an unfortunate event that occurs in families with a poor prevention culture. Its prevalence is unknown in developing countries; it occurs mainly in children < 5 years and is more common in boys. The chemical caustic agents are alkaline (85%) or acid products stored in food or beverage containers without warning labels and safety caps. The immediate symptoms include salivation, oropharyngeal burns, vomiting and oropharyngeal/retrosternal pain. Upper endoscopy is the first‐line tool to identify the type and extension of oesophageal and gastric damage. A barium swallow performed 2–3 weeks after the CI may identify oesophageal stricture. Dysphagia occurs in about one‐third of cases. Regarding the nutritional status, children with dysphagia and/or oesophageal strictures may have lower fat reserves or muscle mass than the cases without these complications, meaning impaired nutritional status. All patients should be hospitalized for evaluation and treatment. Hemodynamic stabilization and adequacy of the patient’s airway are priorities; vomiting induction and gastric lavage are contraindicated. Methylprednisolone in II-b oesophageal burns for 3 days diminishes the risk of stricture. Selected cases will require oesophageal dilatations, gastrostomy or oesophageal replacement by colon or stomach. There are other promising agents in the management of caustic oesophageal strictures

Finding robust solutions for constraint satisfaction problems with discrete and ordered domains by coverings

Constraint programming is a paradigm wherein relations between variables are stated in the form of constraints. Many real life problems come from uncertain and dynamic environments, where the initial constraints and domains may change during its execution. Thus, the solution found for the problem may become invalid. The search forrobustsolutions for constraint satisfaction problems (CSPs) has become an important issue in the ¿eld of constraint programming. In some cases, there exists knowledge about the uncertain and dynamic environment. In other cases, this information is unknown or hard to obtain. In this paper, we consider CSPs with discrete and ordered domains where changes only involve restrictions or expansions of domains or constraints. To this end, we model CSPs as weighted CSPs (WCSPs) by assigning weights to each valid tuple of the problem constraints and domains. The weight of each valid tuple is based on its distance from the borders of the space of valid tuples in the corresponding constraint/domain. This distance is estimated by a new concept introduced in this paper: coverings. Thus, the best solution for the modeled WCSP can be considered as a most robust solution for the original CSP according to these assumptionsThis work has been partially supported by the research projects TIN2010-20976-C02-01 (Min. de Ciencia e Innovacion, Spain) and P19/08 (Min. de Fomento, Spain-FEDER), and the fellowship program FPU.Climent Aunés, LI.; Wallace, RJ.; Salido Gregorio, MA.; Barber Sanchís, F. (2013). Finding robust solutions for constraint satisfaction problems with discrete and ordered domains by coverings. Artificial Intelligence Review. 1-26. https://doi.org/10.1007/s10462-013-9420-0S126Climent L, Salido M, Barber F (2011) Reformulating dynamic linear constraint satisfaction problems as weighted csps for searching robust solutions. 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Different Psychophysiological Responses to a High-intensity Repetition Session Performed Alone or in a Group by Elite Middle-distance Runners

Internal training load refers to the degree of disturbance in psychophysiological homeostasis provoked by a training session and has been traditionally measured through session-RPE, which is the product of the session Rate of Perceived Exertion (RPE) and the duration. External training load refers to the actual physical work completed, and depends on session volume, intensity, frequency and density. Drafting, which is achieved by running closely behind another runner has been demonstrated to reduce the energy cost of running at a fixed speed and to improve performance. Therefore, it is hypothesized that psychophysiological responses might reflect different levels of internal load if training is performed individually or collectively. 16 elite middle-distance runners performed two high-intensity training sessions consisting of 4 repetitions of 500 m separated by 3 minutes of active recovery. Sessions were performed individually and collectively. Times for each repetition, RPE, core affect (valence and felt arousal) and blood lactate concentrations [BLa] were measured after each repetition. Main time effect was significant and increased across repetitions for [BLa] and RPE (p <0.001), and decreased for valence (p =0.001). Main group effect was significant and values were higher when training individually for [BLa] (p =0.003) and RPE (p =0.001), and lower for valence (p =0.001). No differential responses were found between conditions in terms of repeat time or felt arousal. Findings demonstrate that elite middle-distance athletes running collectively display lower levels of internal training load compared to running alone, despite external training load being similar