Unusual co-infection of severe malaria by Plasmodium vivax and dengue virus in Mexico.

Malaria and dengue fever are among the most common mosquito-borne diseases worldwide; however, reports of coinfection are rare. We present a case of severe malaria and dengue coinfection in a 16-yearold female patient presenting with fever, thrombocytopenia, pleural effusion, myopericarditis, and acute respiratory distress syndrome. Dengue infection was confirmed by the presence of immunoglobin M antibodies and nonstructural protein 1, while malaria was confirmed by the presence of Plasmodium vivax in thick and thin blood smears. This is the first report of a dengue/malaria coinfection in Mexico.

Unusual co-infection of severe malaria by Plasmodium vivax and dengue virus in Mexico

@#Malaria and dengue fever are among the most common mosquito-borne diseases worldwide; however, reports of coinfection are rare. We present a case of severe malaria and dengue coinfection in a 16-yearold female patient presenting with fever, thrombocytopenia, pleural effusion, myopericarditis, and acute respiratory distress syndrome. Dengue infection was confirmed by the presence of immunoglobin M antibodies and nonstructural protein 1, while malaria was confirmed by the presence of Plasmodium vivax in thick and thin blood smears. This is the first report of a dengue/malaria coinfection in Mexico.

Detection of Candidatus Bartonella odocoilei n. sp. in Lipoptena mazamae associated with white-tailed deer in Campeche, Mexico.

The deer ked Lipoptena mazamae (Diptera: Hippoboscidae) (Róndani), is a blood-feeding obligate ectoparasite of several species of deer and brocket. However, at present little information is available about its role as a vector of hemoparasites. Nonetheless, it is considered a competent vector for the transmission of Bartonella species. The aim of this study was performing the morphological and molecular identification of ked flies and to carry out the detection of Bartonella. We collected specimens from Chiná, Campeche, Mexico associated with white-tailed deer. Using polymerase chain reaction (PCR), of COI, gltA and rpoB genes, we were able to obtain the first barcode for L. mazamae from Mexico and identified a new species of Bartonella which was found with a prevalence of 73%. The data obtained in this study confirmed the presence of L. mazamae associated with white-tailed deer and its possible role as vector of Candidatus Bartonella odocoilei n. sp. in Mexico and we considered that it may also be present in white-tailed deer populations in the U.S.A. Additional investigations into Bartonella species associated with deer ked could provide further insight into their pathogenicity and its role as a zoonotic agent.

A multi-technique approach to understanding delithiation damage in LiCoO2 thin films.

We report on the delithiation of LiCoO2 thin films using oxalic acid (C2H2O4) with the goal of understanding the structural degradation of an insertion oxide associated with Li chemical extraction. Using a multi-technique approach that includes synchrotron radiation X-ray diffraction, scanning electron microscopy, micro Raman spectroscopy, photoelectron spectroscopy and conductive atomic force microscopy we reveal the balance between selective Li extraction and structural damage. We identify three different delithiation regimes, related to surface processes, bulk delithiation and damage generation. We find that only a fraction of the grains is affected by the delithiation process, which may create local inhomogeneities. However, the bulk delithiation regime is effective to delithiate the LCO film. All experimental evidence collected indicates that the delithiation process in this regime mimics the behavior of LCO upon electrochemical delithiation. We discard the formation of Co oxalate during the chemical extraction process. In conclusion, the chemical route to Li extraction provides additional opportunities to investigate delithiation while avoiding the complications associated with electrolyte breakdown and simplifying in-situ measurements.

Consumer perception and acceptability of microalgae based breadstick.

The demand for sustainable and healthy food is increasing. Therefore, it is necessary to find new sources of functional ingredients for design of novel food products. Microalgae are reliable sources of functional ingredients, ready for exploitation with purpose of production of human food. This work explores consumers' acceptance of novel foods based on microalgae. To achieve natural and realistic eating location, sensory analysis was conducted in a real restaurant in Universitat Politècnica de València. A check-all-that-apply questionnaire and hedonic scale registered the consumers' expectations (N = 85), perceptions and acceptance, before and after taste of typical Valencian breadsticks. Food neophobia can affect acceptability of novel foods, thus, participants completed a test designed to measure their attitudes towards new food. Microalgae breadsticks have distinctive characteristics compared to control breadsticks, such as colour, flavour and odour, because of microalgae presence. Still, those breadsticks were as acceptable as the control breadsticks according to the consumer preferences. Consumers expected more differences amongst both breadsticks before tasting, but they lowered the differences in perception after trying them. Consumers consider that the product is healthier, and they would understand if it had greater expense. We believe this information can be useful for selling / marketing this novel product.

Polarization dependence of second harmonic generation from plasmonic nanoprism arrays.

The second order nonlinear optical response of gold nanoprisms arrays is investigated by means of second harmonic generation (SHG) experiments and simulations. The polarization dependence of the nonlinear response exhibits a 6-fold symmetry, attributed to the local field enhancement through the excitation of the surface plasmon resonances in bow-tie nanoantennas forming the arrays. Experiments show that for polarization of the input light producing excitation of the plasmonic resonances in the bow-tie nanoantennas, the SHG signal is enhanced; this despite the fact that the linear absorption spectrum is not dependent on polarization. The results are confirmed by electrodynamic simulations which demonstrate that SHG is also determined by the local field distribution in the nanoarrays. Moreover, the maximum of SHG intensity is observed at slightly off-resonance excitation, as implemented in the experiments, showing a close relation between the polarization dependence and the structure of the material, additionally revealing the importance of the presence of non-normal electric field components as under focused beam and oblique illumination.

Crystalline Structure and Vacancy Ordering across a Surface Phase Transition in Sn/Cu(001).

We report a surface X-ray diffraction study of the crystalline structure changes and critical behavior across the (3√2 × âˆš2)R45° → (√2 × âˆš2)R45° surface phase transition at 360 K for 0.5 monolayers of Sn on Cu(100). The phase transition is of the order-disorder type and is due to the disordering of the Cu atomic vacancies present in the low temperature phase. Two different atomic sites for Sn atoms, characterized by two different heights, are maintained across the surface phase transition.

Propiedades funcionales de tubérculos nativos de la región andina de Chimborazo (Ecuador): una revisión / Functional properties in Andean native tubers: a review

La región andina de Chimborazo en Ecuador está situada en la zona central de la Región Interandina. La alimentación de las comunidades es esencialmente a base tubérculos (patata, oca, melloco y mashwa), granos (maíz, quinua y amaranto) y de leguminosas (chocho, haba, fréjol). Las características de la región han permitido la supervivencia de este tipo de cultivos que presentan una gran variabilidad en colores, formas y tamaños, y están asociados con cantidad de macro y micronutrientes, además de compuestos bioactivos. El objetivo de este trabajo es revisar los datos existentes sobre los componentes con potencial funcional presentes en los cultivos de tubérculos nativos de la región. Esta información servirá como base para la creación, en la Escuela Superior Politécnica de Chimborazo (ESPOCH), de una línea de investigación que estimule la conservación de estos cultivos como fuente de alimentos funcionales naturales (AU)

Chimborazo in Ecuador is located in the Middle Inter-Andean region. People from this region have utilized native tubers for their nutritional and medicinal properties since pre-hispanic time. The health-related properties of Andean tuber crops claimed from folklore use could be in part attributed to the antioxidants present in these crops. Currently there is a high interest in the search for edible plants as novel sources of health-promoting phytochemicals. Andean crops show variability in colors, forms and sizes, and also in primary nutrient constituents and bioactive secondary metabolites derived of a great genetic diversity, unfortunately poorly studied. The objective of this work is to review the existing data on the components with functional properties in the native tubers. The information extracted in this paper should serve to stimulate an increase in the evaluation of these crops as sources of functional foods, as well as to introduce a new research program in the Escuela Superior Politecnica de Chimborazo (ESPOCH) (AU)

Boundary effects in finite size plasmonic crystals: focusing and routing of plasmonic beams for optical communications.

Plasmonic crystals, which consist of periodic arrangements of surface features at a metal-dielectric interface, allow the manipulation of optical information in the form of surface plasmon polaritons. Here we investigate the excitation and propagation of plasmonic beams in and around finite size plasmonic crystals at telecom wavelengths, highlighting the effects of the crystal boundary shape and illumination conditions. Significant differences in broad plasmonic beam generation by crystals of different shapes are demonstrated, while for narrow beams, the propagation from a crystal onto the smooth metal film is less sensitive to the crystal boundary shape. We show that by controlling the boundary shape, the size and the excitation beam parameters, directional control of propagating plasmonic modes and their behaviour such as angular beam splitting, focusing power and beam width can be efficiently achieved. This provides a promising route for robust and alignment-independent integration of plasmonic crystals with optical communication components.

Physico-Chemical and Structural Characteristics of Vegetables Cooked Under Sous-Vide, Cook-Vide, and Conventional Boiling.

In this paper, physico-chemical and structural properties of cut and cooked purple-flesh potato, green bean pods, and carrots have been studied. Three different cooking methods have been applied: traditional cooking (boiling water at 100 °C), cook-vide (at 80 and 90 °C) and sous-vide (at 80 °C and 90 °C). Similar firmness was obtained in potato applying the same cooking time using traditional cooking (100 °C), and cook-vide and sous-vide at 90 °C, while in green beans and carrots the application of the sous-vide (90 °C) required longer cooking times than cook-vide (90 °C) and traditional cooking (100 °C). Losses in anthocyanins (for purple-flesh potatoes) and ascorbic acid (for green beans) were higher applying traditional cooking. ß-Carotene extraction increased in carrots with traditional cooking and cook-vide (P < 0.05). Cryo-SEM micrographs suggested higher swelling pressure of starch in potatoes cells cooked in contact with water, such as traditional cooking and cook-vide. Traditional cooking was the most aggressive treatment in green beans because the secondary walls were reduced compared with sous-vide and cook-vide. Sous-vide preserved organelles in the carrot cells, which could explain the lower extraction of ß-carotene compared with cook-vide and traditional cooking. Sous-vide cooking of purple-flesh potato is recommended to maintain its high anthocyanin content. Traditional boiling could be recommended for carrots because increase ß-carotenes availability. For green beans, cook-vide, and sous-vide provided products with higher ascorbic acid content.

Shaping plasmon beams via the controlled illumination of finite-size plasmonic crystals.

Plasmonic crystals provide many passive and active optical functionalities, including enhanced sensing, optical nonlinearities, light extraction from LEDs and coupling to and from subwavelength waveguides. Here we study, both experimentally and numerically, the coherent control of SPP beam excitation in finite size plasmonic crystals under focussed illumination. The correct combination of the illuminating spot size, its position relative to the plasmonic crystal, wavelength and polarisation enables the efficient shaping and directionality of SPP beam launching. We show that under strongly focussed illumination, the illuminated part of the crystal acts as an antenna, launching surface plasmon waves which are subsequently filtered by the surrounding periodic lattice. Changing the illumination conditions provides rich opportunities to engineer the SPP emission pattern. This offers an alternative technique to actively modulate and control plasmonic signals, either via micro- and nano-electromechanical switches or with electro- and all-optical beam steering which have direct implications for the development of new integrated nanophotonic devices, such as plasmonic couplers and switches and on-chip signal demultiplexing. This approach can be generalised to all kinds of surface waves, either for the coupling and discrimination of light in planar dielectric waveguides or the generation and control of non-diffractive SPP beams.

On the nonlinear behaviour of nematic single crystal elastomers under biaxial mechanic and electrical force fields.

A slab of nematic-side-chain-liquid-single-crystal elastomer (NSCLSCE), with the director initially oriented in the z -direction, is subjected to a pair of equal mechanical loads and electrical force fields in the x , y directions. The electric fields tend to make easier the rotation of the director after the application of the mechanical force field. A nonlinear expression for the free energy density is used to obtain the interval of stretching for which the system becomes unstable. However, the elastic energy of the network is assumed to be linear. The stress-strain curves predicted by the model show an unstable zone between two linearly increasing segments. The possibility of bifurcation phenomena has been examined.

Paper and pencil vs online self-administered food frequency questionnaire(FFQ) applied to university population: a pilot study / Cuestionario de frecuencia de consumo de alimentos autoadministrado en formato papel vs online aplicado a la población universitaria: un estudio piloto

Objective: To test the reliability of dietary intake data measured with an online food frequency questionnaires (FFQ) applied to a university population by comparing the results with those from a paper and pencil version. Materials and methods: A total of 50 students were recruited from the second-year Food Technology course at the Universitat Politècnica de València (Comunidad Valenciana, Spain) in the academic year 2008-2009. The students were between the ages of 20-32. The participants completed both presentation modes of the FFQ (paper and pencil and online) in a cross-over study with a time interval of 3-week. To study the effect of ordering of the questionnaires, participants were randomly assigned to group A (paper and pencil FFQ first) and group B (online FFQ first). Both self-administered semi-quantitative presentations of the FFQ included 84 food items divided into six groups (dairy products; eggs, meat and fish; vegetables, legumes and fruits; bread, cereals and similar; oils, fats and sweets; beverages and pre-cooked). Participants were asked how frequently and how much each food item they had consumed in the previous year. Results: The response rate was 78% (39 students, 23% men and 77% women). For the total sample, the median dietary intakes were higher for the paper and pencil FFQ than the online version for energy (2,077 vs. 1,635 kcal/day), proteins (96 vs. 88 g/day), carbohydrates (272 vs. 211 g/day), and fat (70 vs. 58 g/day), respectively. These differences were statistically significant. However, there were not significant differences between the two presentations when the consumption by groups of food was calculated, except for ‘beverages and pre-cooked’ group. Conclusions: The pilot testing showed that this online FFQ is a useful tool for estimating the intake of food groups in this university population. On the other hand, the differences found in the results of the absolute quantities of energy and nutrients intakes were not clear. These differences could be due to the problems that the participants had for reporting portion size in the paper and pencil FFQ as photographs of portion sizes were not presented (AU)

Objetivo: Estudiar la fiabilidad de los datos de ingesta dietética medidos con un cuestionario de frecuencia de consumo de alimentos online aplicado a la población universitaria comparando los resultados con los obtenidos mediante el cuestionario en formato papel. Materiales y métodos: Un total de 50 estudiantes del segundo curso de Ciencia y Tecnología de los Alimentos en la Universitat Politècnica de València (Comunidad Valenciana, España) en el año académico 2008-2009 participaron en el estudio. El rango de edad de los participantes oscilaba entre 20 y 32 años. En un estudio cruzado, los participantes completaron ambas presentaciones del cuestionario (formato papel y versión online) en un intervalo de 3 semanas. Para estudiar el efecto del orden de autoadministración de los cuestionarios, los participantes fueron asignados al azar en el grupo A (realizaron primero el cuestionario en formato papel) y en el grupo B (realizaron primero la versión online). Ambas presentaciones del cuestionario eran autoadministradas y semicuantitativas e incluían una lista de 84 alimentos divididos en seis grupos (productos lácteos; huevos, carne y pescado; vegetales, legumbres y frutas; pan, cereales y similares; aceites, grasas y dulces; bebidas y precocinados). Para cada alimento que los participantes habían consumido el año anterior debían indicar la frecuencia y la cantidad consumida. Resultados: La tasa de respuesta fue del 78% (39 estudiantes, 23% hombre y 77% mujeres). Para el total de la muestra, la mediana de la ingesta dietética fue mayor en el cuestionario en papel que en la versión online para la energía (2.077 vs 1.635 kcal/día), las proteínas (96 vs 88 g/día), los hidratos de carbono (272 vs 211 g/día) y las grasas (70 vs. 58 g/día), respectivamente. Estas diferencias fueron estadísticamente significativas. Sin embargo, no hubieron diferencias significativas entre ambas presentaciones cuando el consumo por grupos de alimentos fue calculado, excepto para el grupo de ‘bebidas y precocinados’. Conclusiones: El estudio piloto mostró que este cuestionario online es una herramienta útil para estimar la ingesta de los grupos de alimentos en esta población universitaria. En cambio, las diferencias encontradas en los resultados de energía y nutrientes no fueron concluyentes. Éstas pudieron deberse a los problemas que tuvieron los participantes para indicar el tamaño de porción ingerida en el cuestionario en papel porque las fotografías de los tamaños de ración no se mostraban (AU)

Design of a self-administered online food frequency questionnaire (FFQ) to assess dietary in take among university population / Diseño de un cuestionario de frecuencia de consumo de alimentos autoadministrado online para evaluar la ingesta dietetica de la población universitaria

Objective: To introduce and describe a new tool called UPV-FFQ to evaluate dietary intake of the university population. The new tool consists principally in a selfadministered online food frequency questionnaire (FFQ). Materials and methods: The tool UPV-FFQ has been developed by means of web pages applying the technology ASP.NET 2.0 and using the database SQL Server 2005 as support. To develop the FFQ has been used as model the paper and pencil FFQ called "Dieta, salud y antropometría en la población universitaria". Results: The tool has three parts: (1) a homepage, (2) a general questionnaire and (3) a FFQ. The FFQ has a closed list of 84 food items commonly consumed in Valencia region. The respondents has to indicate the food items that they consume (2 possible options), the frequency of consumption (9 response options) and the quantity consumed (7 response options). The UPV-FFQ has approximately 250 color photographs that represents to three portion sizes. The photographs are useful to help the respondents to choose the portion sizes that more adjusts to their habitual portions. The new tool provides quantitative information of the habitual intake of 31 nutritional parameters and provides qualitative information of the general questionnaire. A pilot study was done for a total of 57 respondents. The media time spend to fill in was 15 minutes. Conclusions: The pilot study concluded that the questionnaire was ease-of-use, low cost and time-effectiveness questionnaire. The format and the sequence of the questions were easily understood (AU)

Objetivo: Introducir y describir una nueva herramienta llamada UPV-FFQ para evaluar la ingesta dietética de la población universitaria. Esta nueva herramienta consiste principalmente en un cuestionario de frecuencia de consumo de alimentos (CFCA) autoadministrado online. Materiales and métodos: La herramienta UPV-FFQ se ha desarrollado a través de páginas web aplicando la tecnología ASP.NET 2.0 y usando la base de datos SQL Server 2005 como soporte. Para desarrollar este FFQ se ha empleado como modelo el cuestionario en papel llamado ‘Dieta, salud y antropometría en la población universitaria’. Resultados: La herramienta consta de tres partes: 1) una página de introducción; 2) un cuestionario general y 3) un CFCA. El CFCA consta de una lista cerrada de 84 alimentos comúnmente consumidos en la región valenciana. Los encuestados deben indicar qué alimentos consumen (2 posibles opciones de respuesta), la frecuencia de ingesta (9 opciones de respuesta) y la cantidad ingerida (7 opciones de respuesta). El UPV-FFQ presenta aproximadamente 250 fotografías a color con tamaños de ración para cada alimento para ayudar a los encuestados a escoger el tamaño de ración que más se ajusta a su porción habitual. La herramienta proporciona información cuantitativa de la ingesta habitual de 31 parámetros nutricionales y también proporciona información cualitativa proveniente del cuestionario general. Se realizó un estudio piloto con un total de 57 participantes con características similares a la población de estudio. El tiempo medio que emplearon para rellenarlo fue de 15 minutos. Conclusiones: El estudio piloto concluyó que el UPVFFQ era fácil de manejar, de bajo coste y de gran eficacia. Además, entendieron fácilmente el formato y la secuencia de las preguntas (AU)

New technologies applied to food frequency questionnaires: a current perspective / Nuevas tecnologías aplicadas a los cuestionarios de frecuencia de consumo de alimentos: una perspectiva actual

The food frequency questionnaires are widely used in epidemiological researches like dietary assessment method. Traditionally, they have been self-administered in paper but the use of information and communication technologies has led to develop Internet and computerized food frequency questionnaires. It is the objective of this article to offer a global perspective of the new technologies applied to FFQ. It will be presented the purpose of the food frequency questionnaire, the number of strengths of the web-based surveys versus print-surveys and finally, a description of the manuscripts that have used web-based and computerized FFQ (AU)

Los cuestionarios de frecuencia de consumo de alimentos son muy utilizados en investigaciones epidemiológicas como método para evaluar la dieta. Tradicionalmente, han sido autoadministrados en papel, pero el uso de las tecnologías de la información y la comunicación (TICs) ha permitido desarrollar cuestionarios de frecuencia de consumo de alimentos computerizados y a través de Internet. El objetivo de este artículo es ofrecer una perspectiva actual del uso de las nuevas tecnologías aplicadas al diseño e interpretación de los cuestionarios de frecuencia de consumo de alimentos. En el presente trabajo se resumen los objetivos de los cuestionarios de frecuencia de consumo de alimentos, las ventajas de los cuestionarios autoadministrados por Internet frente a los administrados en papel y finalmente, se describirán diferentes estudios que han usado cuestionarios de frecuencia de consumo de alimentos autoadministrados mediante el uso de ordenador o a través de Internet (AU)

New technologies applied to food frequency questionnaires: a current perspective.

The food frequency questionnaires are widely used in epidemiological researches like dietary assessment method. Traditionally, they have been self-administered in paper but the use of information and communication technologies has led to develop Internet and computerized food frequency questionnaires. It is the objective of this article to offer a global perspective of the new technologies applied to FFQ. It will be presented the purpose of the food frequency questionnaire, the number of strengths of the web-based surveys versus print-surveys and finally, a description of the manuscripts that have used web-based and computerized FFQ.

Paper and pencil vs online self-administered food frequency questionnaire (FFQ) applied to university population: a pilot study.

OBJECTIVE: To test the reliability of dietary intake data measured with an online food frequency questionnaires (FFQ) applied to a university population by comparing the results with those from a paper and pencil version. MATERIALS AND METHODS: A total of 50 students were recruited from the second-year Food Technology course at the Universitat Politècnica de València (Comunidad Valenciana, Spain) in the academic year 2008-2009. The students were between the ages of 20-32. The participants completed both presentation modes of the FFQ (paper and pencil and online) in a cross-over study with a time interval of 3-week. To study the effect of ordering of the questionnaires, participants were randomly assigned to group A (paper and pencil FFQ first) and group B (online FFQ first). Both self-administered semi-quantitative presentations of the FFQ included 84 food items divided into six groups (dairy products; eggs, meat and fish; vegetables, legumes and fruits; bread, cereals and similar; oils, fats and sweets; beverages and pre-cooked). Participants were asked how frequently and how much each food item they had consumed in the previous year. RESULTS: The response rate was 78% (39 students, 23% men and 77% women). For the total sample, the median dietary intakes were higher for the paper and pencil FFQ than the online version for energy (2,077 vs. 1,635 kcal/day), proteins (96 vs. 88 g/day), carbohydrates (272 vs. 211 g/day), and fat (70 vs. 58 g/day), respectively. These differences were statistically significant. However, there were not significant differences between the two presentations when the consumption by groups of food was calculated, except for "beverages and pre-cooked" group. CONCLUSIONS: The pilot testing showed that this online FFQ is a useful tool for estimating the intake of food groups in this university population. On the other hand, the differences found in the results of the absolute quantities of energy and nutrients intakes were not clear. These differences could be due to the problems that the participants had for reporting portion size in the paper and pencil FFQ as photographs of portion sizes were not presented.

Design of a self-administered online food frequency questionnaire (FFQ) to assess dietary intake among university population.

OBJECTIVE: To introduce and describe a new tool called UPV-FFQ to evaluate dietary intake of the university population. The new tool consists principally in a self-administered online food frequency questionnaire (FFQ). MATERIALS AND METHODS: The tool UPV-FFQ has been developed by means of web pages applying the technology ASP.NET 2.0 and using the database SQL Server 2005 as support. To develop the FFQ has been used as model the paper and pencil FFQ called "Dieta, salud y antropometría en la población universitaria". RESULTS: The tool has three parts: (1) a homepage, (2) a general questionnaire and (3) a FFQ. The FFQ has a closed list of 84 food items commonly consumed in Valencia region. The respondents has to indicate the food items that they consume (2 possible options), the frequency of consumption (9 response options) and the quantity consumed (7 response options). The UPV-FFQ has approximately 250 color photographs that represents to three portion sizes. The photographs are useful to help the respondents to choose the portion sizes that more adjusts to their habitual portions. The new tool provides quantitative information of the habitual intake of 31 nutritional parameters and provides qualitative information of the general questionnaire. A pilot study was done for a total of 57 respondents. The media time spend to fill in was 15 minutes. CONCLUSIONS: The pilot study concluded that the questionnaire was ease-of-use, low cost and time-effectiveness questionnaire. The format and the sequence of the questions were easily understood.

Electronic structure of Sn/Cu(100)-[Formula: see text].

We present measurements of the Fermi surface and underlying band structure of Sn/Cu(100)-[Formula: see text]. This phase is observed for a coverage of 0.60-0.65 monolayers. Its electronic structure is characterized by a free-electron-like surface band folded with the reconstruction periodicity. At variance with other surface phases of Sn on Cu(100), no temperature-induced phase transition is observed for this phase from 100 K up to the desorption of Sn.

Surface x-ray diffraction analysis using a genetic algorithm: the case of Sn/Cu(100)-[Formula: see text].

The application of genetic algorithms to the analysis of surface x-ray diffraction data is discussed and the implementation of a genetic algorithm of evolutionary type is described in detail. The structure of Sn/Cu(100)-[Formula: see text] is determined on the basis of surface x-ray diffraction data analysed using this algorithm. The results are compared to previous findings using other techniques.