Observation of Polarization Singularities and Topological Textures in Sound Waves.

Polarization singularities and topological polarization structures are generic features of inhomogeneous vector wave fields of any nature. However, their experimental studies mostly remain restricted to optical waves. Here, we report the observation of polarization singularities, topological Möbius-strip structures, and skyrmionic textures in 3D polarization fields of inhomogeneous sound waves. Our experiments are made in the ultrasonic domain using nonparaxial propagating fields generated by space-variant 2D acoustic sources. We also retrieve distributions of the 3D spin density in these fields. Our results open the avenue to investigations and applications of topological features and nontrivial 3D vector properties of structured sound waves.

[Life style and monitoring of the dietary intake of students at the Melilla campus of the University of Granada]. / ESTILO DE VIDA Y SEGUIMIENTO DE LA INGESTA DIETÉTICA EN ESTUDIANTES DEL CAMPUS DE LA UNIVERSIDAD DE GRANADA EN MELILLA.

INTRODUCTION: University students represent a social group at risk, from the nutrionally point of view because they usually have inappropiate nutritional habits and lifestyle. OBJECTIVE: Analize the students' lifestyle from the Campus of University of Granada in Melilla. Analize the evolution of the eating habits of these students during the academic year 2013-2014. METHODS: A longitudinal study was carried out during the academic year 2013-2014, the lifestyle was evaluated and, in a ongoing way, the eating habits in a representative sample of 257 students, 90 men (35%) and 167 women (65%), all of them from the campus of University of Granada in Melilla. RESULTS: The results get worst as the academic year progresses and they are characterized by a significant reduction (p < 0.001) of carbohydrates intake as well as a significant increase (p < 0.001) of the lipido and proteína intake, especially, rich in saturated fat and a low-fiber diet. CONCLUSIONS: The population studied shows a sedentary lifestyle. As the academic year progresses, the students' eating habits get worst distance from the Mediterranian Diet pattern with the consequent risk at the development of cardiovascular diseases and metabolism disorder. So, it is necesary to get into these results in order to identify the influential factors in their eating habits and take the appropiate actions.

Introducción: los estudiantes universitarios representan un colectivo social en riesgo desde el punto de vista nutricional, ya que a menudo mantienen estilos de vida y hábitos nutricionales inapropiados. Objetivos: analizar el estilo de vida de los alumnos del Campus de la Universidad de Granada en Melilla. Analizar la evolución de los hábitos alimentarios de los estudiantes del campus durante el curso académico 2013-2014. Material y método: se realizó un estudio longitudinal durante el curso académico 2013-2014 en el cual, a su inicio, se evaluó el estilo de vida y, de forma continuada los hábitos nutricionales de un grupo representativo de 257 estudiantes, 90 chicos (35%) y 167 chicas (65%), todos ellos del campus de la Universidad de Granada en la Ciudad Autónoma de Melilla (norte de África). Resultados: los hábitos nutricionales empeoran a medida que avanza el curso académico, caracterizándose por una reducción significativa (p < 0.001) en la ingesta de carbohidratos, así como por una elevación significativa (p < 0.001) en la ingesta proteica y lipídica, siendo especialmente rica en grasas saturadas y baja en fibra. Conclusiones: la población estudiada posee un estilo de vida eminentemente sedentario. A medida que avanza el curso académico, los hábitos nutricionales de los estudiantes empeoran, alejándose del patrón de alimentación mediterráneo con el consiguiente riesgo de desarrollar enfermedades metabólicas y cardiovasculares. De estos resultados se desprende la necesidad de continuar profundizando a fin de identificar los factores que influyen en sus hábitos nutricionales y establecer las medidas correctoras oportunas.

[Evaluation of the nutritional status, insulin resistance and cardiovascular risk in a population of adolescents in the cities of Granada and Almeria (Spain)]. / Valoración del estado nutricional, resistencia insulínica y riesgo cardiovascular en una población de adolescentes de la ciudades de Granada y Almería.

OBJECTIVES: The first objective of this study was to evaluate the nutritional status and insulin resistance index in a population of adolescents as calculated by Homeostatic Model Assessment (HOMA). The second objective was to establish correlations between the nutritional status of the subjects, the possible existence of insulin resistance, and the risk of high blood pressure. POPULATION SAMPLE AND METHODOLOGY: The sample was composed of 1001 adolescents, 9-17 years of age, from 18 schools in the provinces of Granada and Almeria. Their nutritional status was determined by means of anthropometric evaluation. For the metabolic study, a blood sample was collected from each subject by venipuncture. An analysis was performed of the basal glucose and insulin levels as well as the Homeostatic Model Assessment- Insulin Resistance (HOMAIR) index. Also evaluated were the levels of glycosylated haemoglobin (HbA1c), serum lipoprotein (a), and non-esterified fatty acids (NEFAs). Insulin resistance was calculated with the formula, proposed by Matthews et al. (1985) : HOMA-IR = (insulin[mmol/L] x glucose[mU/L])/22.5. RESULTS: The evaluation of the nutritional status of the subjects reflected a progressive increase in the values of anthropometric variables as the nutritional status of the subjects worsened. The results of this study showed, regardless of age and gender, 85.01% of the subjects were of normal weight, whereas 9.99% were overweight, and 4.99% were obese. The metabolic study reflected that in comparison to normal-weight and overweight students, obese students had significantly higher serum levels (p < 0,0001) of HbA1c, basal insulin, basal glycemia, basal NEFA, lipoprotein (a), and HOMA-IR. CONCLUSIONS: Obesity was found to be a serious health problem in the population of adolescents studied, especially given the high cardiovascular risk that is characteristic of this condition. As reflected in the results of this study, obesity led to the premature development of metabolic disorders, which generally do not appear until adulthood.

Objetivos: Los objetivos de este estudio fueron evaluar el estado nutricional e índice de resistencia insulínica mediante HOMA en una población de adolescentes, así como establecer correlaciones entre el estado nutricional de los sujetos, la existencia o no de resistencia a la acción insulínica y el riesgo de padecer hipertensión arterial. Muestra y metodología: Una población de 1001 adolescentes de entre 9 y 17 años de edad, pertenecientes a 18 centros educativos de las provincias de Granada y Almería. Se realizó una valoración completa del estado nutricional de los alumnos mediante antropometría. Para el estudio metabólico, se practicó una extracción sanguínea mediante punción venosa a cada alumno, analizando glucosa basal, insulina basal, índice HOMAIR. Además, se valoró hemoglobina glicosilada (HBA1c), niveles séricos de lipoproteína (a) y ácidos grasos de cadena larga (NEFA). Para el cálculo del índice de resistencia a la insulina, se utilizó el modelo matemático propuesto por Matthews (Homeostasis Model Assessment - HOMAIR), aplicando la fórmula HOMAIR = (insulina x glucosa)/22,5. Resultados: La valoración del estado nutricional reveló un progresivo incremento en los valores de las variables antropométricas a medida que el estado nutricional de los sujetos empeoraba, describiéndose una prevalencia de normopeso del 85,01%, frente a una tasa de sobrepeso del 9,99% y de obesidad del 4,99% para ambos sexos y con independencia de la edad. El estudio metabólico evidenció niveles séricos significativamente más elevados (p < 0,0001) de HBA1c, insulina basal, glucemia basal, NEFA basal, lipoproteína (a) y HOMA IR entre adolescentes con obesidad frente a aquellos otros en situación de normopeso o sobrepeso. Conclusiones: La obesidad constituye un grave problema de salud entre la población de adolescentes estudiada, determinado el desarrollo precoz de trastornos metabólicos, hasta ahora propios de la etapa adulta circunstancia ésta alarmante si consideramos el riesgo cardiovascular que ello implica.

Three-dimensional accelerating electromagnetic waves.

We present a general theory of three-dimensional non-paraxial spatially-accelerating waves of the Maxwell equations. These waves constitute a two-dimensional structure exhibiting shape-invariant propagation along semicircular trajectories. We provide classification and characterization of possible shapes of such beams, expressed through the angular spectra of parabolic, oblate and prolate spheroidal fields. Our results facilitate the design of accelerating beams with novel structures, broadening scope and potential applications of accelerating beams.