Algebraic Integration of Sigma Model Field Equations

We prove that the dualization algebra of the symmetric space coset sigma model is a Lie algebra and we show that it generates an appropriate adjoint representation which enables the local integration of the field equations yielding the first-order ones.Comment: 27p

Preparación y caracterización de oleogeles con sebo y sebo parcialmente hidrolizado como organogeladores

The aim of this study was to evaluate the organogelation potential of tallow fat (TF) and partially hydrolyzed tallow fat (HTF) against saturated monoglyceride (MG) and a saturated monoglyceride + diglyceride mixture (MDG) as the organogelators. TF itself created oleogel at a 30% addition level, while HTF, MG and MDG oleogels were prepared at 10% addition levels. Fatty acid composition data showed that the oleogel of HTF (HTFO) was quite similar to those of MG and MDG oleogels. Solid fat content, free fatty acidity and peroxide values were found to be in acceptable ranges for HTFO. Thermal properties, crystal morphology and X-ray diffraction patterns were also evaluated. Rheological analyses indicated that all oleogels had higher storage modulus (G´) than loss modulus (G´´). The time-sweep test showed that after applying higher shear rates, the gels re-formed at rest. Further, all oleogels maintained their gelled consistency until around 54 °C. The results suggest that HTF could be a cheap, efficient, fast melting, safe and readily available organogelator.El objetivo de este estudio fue evaluar el potencial de la organogelación de grasa de sebo (GS) y grasa de sebo parcialmente hidrolizada (GSH) contra monoglicéridos saturados (MG) y mezcla de monoglicéridos + diglicéridos saturados (MDG) como organogelantes. Con la propia GS se creó un oleogel con un nivel de adición del 30%, mientras que los oleogeles de GSH, MG y MDG se prepararon con niveles de adición del 10%. Los datos de composiciones de ácidos grasos mostraron que el oleogel de GSH (OGSH) era bastante similar a los oleogeles de MG y MDG. El contenido de grasa sólida, la acidez grasa libre y los valores de peróxido se encuentran en rangos aceptables para OGSH. También se evaluaron las propiedades térmicas, la morfología del cristal y los patrones de difracción de rayos X. Los análisis reológicos indicaron que todos los oleogeles tenían un módulo de almacenamiento (G´) mayor que el módulo de pérdida (G´´). La prueba de barrido de tiempo mostró que después de aplicar velocidades de cizallamiento más altas, los geles se reformaron en reposo. Además, todos los oleogeles protegieron su consistencia gelificada hasta alrededor de 54 °C de temperatura. Los resultados han sugerido que GSH podría ser un organogelador barato, eficiente, de fusión aguda, seguro y fácilmente disponible

Oleogeles de aceites de oliva virgen con cera de carnaúba y monoglicéridos como productos para untar

The oleogels of virgin olive oil with carnauba wax and monoglyceride were prepared to determine the most suitable spreadable product. The oil binding capacities of monoglyceride oleogels were higher than those of the carnauba wax oleogels. There was no true crystalline structure with carnauba wax at 3%. Although the highest solid fat content was in the 10% monoglyceride oleogel (9.38%), it was 12.15% in the commercial breakfast margarine at 20 °C. The peak melting temperature of the margarine was 47.11 °C, and among all oleogels, monoglyceride oleogel at 7% addition had the closest value (48.70 °C). The melting enthalpies of the oleogels ranged from 1.25 to 103.97 J·g−1, while it was 94.19 J·g−1 for the margarine sample. The firmness and stickiness values were usually lower in the oleogel samples than those of the margarine sample. There was no significant change in the texture parameters during storage, indicating good structural stability. The polarized light microscopy pictures revealed rod-like crystals for carnauba wax and rosette-like aggregates for monoglyceride oleogels. X-ray diffraction patterns of the samples have revealed a β´-type polymorphic structure for the oleogels. These oleogels can be used in a spreadable, breakfast margarin-like product to promote new consumption habits for this healthy oil.Se prepararon oleogeles de aceites de oliva virgen con cera de carnaúba y monoglicéridos para encontrar el producto más adecuado para untar. La capacidad de unión de aceites de oleogeles de monoglicéridos fue más alto que el de los oleogeles de cera de carnaúba. No hubo ninguna estructura cristalina verdadera con cera de carnaúba al 3%. Aunque el mayor contenido de grasa sólida fue con el 10 % de oleogeles de monoglicérido (9,38 %), fue del 12.15 % en el de margarina comercial a 20 °C. La temperatura pico de fusión de la margarina fue 47,11 ºC, y entre todos los oleogeles, los de monoglicérido al 7 % tuvo el valor más próximo (48,70 °C). La entalpía de fusión de los oleogeles estaban en el rango entre 1,25 y 103,97 J·g−1 , mientras que fue de 94,19 J·g−1 para la muestra de la margarina. Los valores de firmeza y adherenciafueron por lo general más bajas en las muestras de oleogeles que en la muestra de margarina. Mientras que no hubo cambios significativos en los parámetros de textura durante el almacenamiento, indicando una buena estabilidad estructural. Las imágenes de microscopía de luz polarizada reveló cristales en forma de varilla de cera de carnauba y agregados en forma de rosetones para los oleogeles monoglicéridos. Los diagramas de difracción de rayos X de las muestras reveló tener estructura polimórfica estándar tipo-β´ para los oleogeles. Estos oleogeles pueden ser productos tipo margarina untable para el desayuno y proporcionar nuevos hábitos de consumo saludable

Integrated Lax Formalism for PCM

By solving the first-order algebraic field equations which arise in the dual formulation of the D=2 principal chiral model (PCM) we construct an integrated Lax formalism built explicitly on the dual fields of the model rather than the currents. The Lagrangian of the dual scalar field theory is also constructed. Furthermore we present the first-order PDE system for an exponential parametrization of the solutions and discuss the Frobenious integrability of this system.Comment: 24 page

Aceite de semilla de cardo mariano prensado en frío: propiedades físico-químicas, composición y análisis sensorial

Cold pressed oil was produced from milk thistle seeds, and its composition and sensorial properties were determined. The seeds were found to contain 14.98% oil, 17.31% protein and 4.14% ash. The peroxide value of the oil (11.39 meqO2/kg oil) was within acceptable limits according to codex, but the free fatty acidity value (3.45%) exceeded the limit. The oil melted at -20.18 °C and crystallized at -3.71 °C. Linoleic acid (51.97%), β-sitosterol (67.56 mg/100 g oil) and γ-tocopherol (53.60 mg/kg oil) were determined as the main components, respectively. Six sensory descriptive terms (sweet, spicy, raw vegetable, straw, roasted and throat-catching) were described for the oil. Consumer tests proved that cold-pressed milk thistle seed oil had intermediate acceptance scores and consumer satisfaction was moderate. In conclusion, it is thought that milk thistle seeds could be used for the production of edible gourmet oil. Further studies regarding the composition of the bio-active molecules in the oil are anticipated.Se obtuvo aceite prensado en frío a partir de semillas de cardo mariano y se determinó su composición y propiedades sensoriales. Se encontró que las semillas contenían 14,98% de aceite, 17,31% de proteína y 4,14% de ceniza. El índice de peróxido del aceite (11,39 meqO2/kg de aceite) se encontraba dentro del límite aceptable según el Codex, pero el índice de acidez libre (3,45 %) excedía el límite. El aceite fundió a -20,18°C y cristalizó a -3,71°C. Se determinaron como componentes principales el ácido linoleico (51,97%), β-sitosterol (67,56 mg/100 g de aceite) y γ-tocoferol (53,60 mg/kg de aceite), respectivamente. Se describieron en el aceite seis términos descriptivos sensoriales: dulce, picante, vegetal crudo, pajizo, asado y pegajoso. Las pruebas de consumo demostraron que el aceite de semilla de cardo mariano prensado en frío tenía puntuaciones de aceptación intermedias y la satisfacción del consumidor era moderada. En conclusión, se cree que las semillas de cardo mariano podrían utilizarse para la producción de aceite gourmet comestible. Se requieren más estudios sobre la composición de moléculas bioactivas del aceite

Evaluation of the relationship between stylohyoid complex morphology and maxillary/mandibular position using cone beam computed tomography

Background: The aim of this study was to examine the morphologic features of the stylohyoid complex (SHC) and its relation to maxillomandibular position using three-dimensional cone beam computed tomography (CBCT) images. Materials and methods: CBCT images from 157 individuals (74 females, 83 males) were analysed in this study. SHC length, width, and sagittal and transverse angles were measured. The subjects were grouped as skeletal class I, II, and III in order to determine the relative positions of the maxilla and mandible in the sagittal plane and as hypodivergent, normodivergent, and hyperdivergent according to the vertical rotation of the mandible in relation to the skull base. Mann-Whitney U and Kruskal-Wallis H tests were used for statistical analysis. Results: Mean SHC length was 23.56 ± 8.05 mm on the right side and 22.0 ± 6.51 mm on the left; mean SHC width was 3.31 ± 1.40 mm on the right and 2.93 ± 1.30 mm on the left. Mean sagittal angle was 27.43 ± 6.75° on the right side, 27.70 ± 6.51° on the left; mean transverse angle was 70.39 ± 4.59° on the right side and 71.79 ± 4.99° on the left. The only significant difference based on skeletal classification was greater SHC length among males compared to females in the class III group (p < 0.05). Conclusions: No significant relationship was observed between SHC morphology and position of the maxilla or mandible. However, the gender difference observed among class III subjects suggests that SHC morphology may be affected by craniofacial morphology. Maxillofacial surgeons should investigate this anatomical landmark variation before surgical interventions involving this region, such as temporomandibular joint procedures

Caracterización integral de las propiedades fisicoquímicas, térmicas, composicionales y sensoriales del aceite de semilla de rosa mosqueta prensado en frío

In this study, cold-pressed rosehip seed oil was fully characterized. Acidity and oxidation levels were near the limit values or slightly exceeded them and improvement in the storage conditions was suggested. The oil started to crystallize at -45.25 °C, and melt at -25.56 °C. Linoleic acid (51.1%), β-sitosterol (84.6%), γ-tocopherol (773.76 µg/g) and rosmarinic acid (31.38 µg/g) were determined as major fatty acid, sterol, tocopherol and phenolic compound, respectively. For the first time, aromatic volatile compounds and sensory descriptive terms were determined for cold-pressed rosehip seed oil. Sixty-seven volatile compounds were detected and L-limonene was found to be a major volatile compound. According to the sensory analysis, timber/kindling and raw vegetable tastes/aromas were found to be relatively dominant. Consequently, it is thought that rosehip seeds can be used as a raw material for edible and nutritionally-rich cold-pressed oil production and/or as source oil for functional food preparations.En este estudio se caracterizó completamente el aceite de semilla de rosa mosqueta prensado en frío. Los niveles de acidez y oxidación estaban cerca de los valores límite o los excedían ligeramente y se sugirió mejorar las condiciones de almacenamiento. El aceite comenzó a cristalizar a -45,25°C y a fundirse a -25,56°C. Se determinó el ácido linoleico (51,1%), β-sitosterol (84,6%), γ-tocoferol (773,76 µg/g) y ácido rosmarínico (31,38 µg/g) como principal ácido graso, esterol, tocoferol y compuesto fenólico, respectivamente. Por primera vez, se determinaron compuestos aromáticos volátiles y términos descriptivos sensoriales para el aceite de semilla de rosa mosqueta prensado en frío. Se detectaron sesenta y siete compuestos volátiles y se descubrió que el L-limoneno era un compuesto volátil importante. Según el análisis sensorial, se encontró que los sabores/aromas de madera/astillas y vegetales crudos eran relativamente dominantes. En consecuencia, se cree que las semillas de rosa mosqueta pueden usarse como materia prima para la producción de aceite prensado en frío comestible y nutritivo y/o como aceite fuente para preparaciones de alimentos funcionales

Aplicación de EOMs y arcillas naturales para la eliminación de MCPD y EG de aceites comestibles

The aim of this study was to investigate the removal of 3-monochloropropane-1,2-diol (3-MCPD) and glycidyl esters (GEs) from edible oils by using Metal Organic Frameworks (MOF) and natural clays. First, the model oil was treated with adsorbents and titanium (IV) butoxide-terephthalate MOF (Ti-MOF) and kaolin were selected as the best performing MOF along with natural clay, respectively, for the removal of 3-MCPD and GEs. The effects of treatment conditions were also investigated, 6.0% adsorbent level, 120 min treatment time and 95 ºC temperature were determined to be the best treatment parameters. Finally, palm oil samples were treated with Ti-MOF and kaolin under the selected conditions and removal of 3-MCPD and GEs was obtained at up to 27% and 58%, respectively. In conclusion, MOFs and natural clays showed good potential for the removal of 3-MCPD and GEs, and the efficiency of the treatment can be improved by modifying the adsorbents.El objetivo de este estudio fue investigar la eliminación de 3-monocloropropano-1,2-diol (3-MCPD) y ésteres de glicidilo (EG) de aceites comestibles mediante el uso de estructuras orgánicas metálicas (EOMs) y arcillas naturales. El aceite modelo se trató en primer lugar con adsorbentes, se seleccionaron titanium (IV) tereftalato de butóxido (Ti-EOM) y caolín como EOM y arcilla natural, respectivamente, para el mejor rendimiento en la eliminación de 3-MCPD y EG. También se investigaron los efectos de las condiciones de tratamiento y se seleccionaron como los mejores parámetros un nivel de adsorbente de 6,0%, un tiempo de tratamiento de 120 min y temperatura de tratamiento de 95ºC. Finalmente, las muestras de aceite de palma se trataron con Ti-EOM y caolín en las condiciones seleccionadas y se obtuvo una eliminación de 3-MCPD y EG de hasta 27% y 58%, respectivamente. En conclusión, los EOMs y las arcillas naturales mostraron un buen potencial para la eliminación de 3-MCPD y EG, y la eficiencia del tratamiento se puede mejorar modificando los adsorbentes

The impact of heavy (excessive) video gaming students on peers and teachers in the school environment: a qualitative study

Video gaming has now become very popular among children and adolescents. Because of the increasing use of videogames, the debate concerning the effects of video games has been ongoing, particularly in terms of gamers’ social lives. This study explores the impact of heavy gaming students on their peers and teachers in the school environment. For this purpose, focus-group and face-to-face interviews have been carried out using semi-structured interview forms developed by the research team. The data have been collected from 21 participants comprised of three heavy gaming students, 16 peers, and two teachers. The findings indicate heavy gamers to display problematic behaviors including communication and behavioral problems within the school environment. Results also show heavy gaming students to prefer staying at home and playing videogames rather than attending school activities. Heavy gamers mostly prefer spending time with other heavy gamers or with male peers because they have mutual topics they can talk about (video games, their game talents, soccer, outdoor games etc.), which they are unable to with girls. According to the teachers, heavy gamers have low-school performance. However, the English teacher emphasized the positive effects of video gaming on students' English vocabulary