Infinite-dimensional representations of the rotation group and Dirac's monopole problem

Within the context of infinite-dimensional representations of the rotation group the Dirac monopole problem is studied in details. Irreducible infinite-dimensional representations, being realized in the indefinite metric Hilbert space, are given by linear unbounded operators in infinite-dimensional topological spaces, supplied with a weak topology and associated weak convergence. We argue that an arbitrary magnetic charge is allowed, and the Dirac quantization condition can be replaced by a generalized quantization rule yielding a new quantum number, the so-called topological spin, which is related to the weight of the Dirac string.Comment: JHEP style. Extended version of hep-th/0403146. Revised version, title and some notations are changed. References and Appendix B are adde

Kisspeptina en becerras prepúberes: I. Influencia de la edad en la respuesta de LH, FSH y GH a kisspeptina-10 y su asociación con IGF-I, leptina y estradiol

To evaluate effects of age on the response of LH, FSH and GH to kisspeptin-10 (KISS) in prepubertal heifers and its association with circulating levels of IGF-I, estradiol (E2) and leptin, 21 heifer calves that were 4, 7 or 11 mo old, received an iv injection of KISS (5 μg/kg). LH, FSH and GH were quantified in blood serum taken every 15 min (4 h pre- and 4 h post-KISS-10). In three pre- and six post-KISS samples, IGF-I, leptin and E2 were determined. All heifers responded to KISS with an LH increment but the response magnitude differed among groups since maximum value was higher (P<0.05) in 11 mo (11.6+1.3 ng/ml) than in 7 mo (7.2±1.3 ng/ml) and 4 mo (6.1±1.3 ng/ml) old calves. Duration of response differed (P<0.05) among ages (11 mo=132.9+20 mina; 7 mo=92±20 mina,b; 4 mo=64.3±20 minb). For FSH, all and 11 mo calves responded to KISS but only 71.4 % of 4 mo did. In GH, 71.4 % of 4 mo and 85.7 % of 7 mo calves responded to KISS whereas 100 % of 11 mo animals responded. FSH and GH did not differ among age groups. The 11 mo heifers had the highest IGF-I and E2 but the lowest leptin levels. In conclusion, KISS evokes LH increments in all calves 4 to 11 mo old, but the response increases with age in association with high circulating IGF-I and E2 and low leptin. The response of FSH and GH to KISS is not influenced by age or variations in circulating IGF-I, E2 or leptin. El objetivo fue evaluar la respuesta de LH, FSH y GH a kisspeptina-10 (KISS) en becerras prepúberes de distintas edades, y su asociación con IGF-I, E2 y leptina circulantes. A 21 becerras de 4, 7 y 11 meses de edad se les aplicó una inyección i.v. de 5 µg de KISS/kg de peso. En suero obtenido de la yugular (cada 15 min, 4 h pre hasta 4 h post-KISS) se cuantificó LH, FSH y GH. En nueve muestras (tres pre y seis post-KISS) se determinó IGF-I, leptina y estradiol (E2). En todas las becerras aumentó la LH post-KISS, con un valor máximo (6.1±1.3a, 7.2±1.3a, 11.6+1.3b ng/ml) y duración de respuesta (64.3±20a, 92±20b, 132.9+20c min) que aumentó (P<0.05) con la edad. Para FSH, 71.4, 100 y 100 % de las becerras de 4, 7 y 11 meses respondieron a KISS-10; situación que para GH fue 71.4, 85.7 y 100 %, respectivamente. La magnitud de la respuesta de FSH y GH a KISS fue similar entre edades. Las becerras de 11 meses tuvieron las máximas concentraciones de IGF-I y E2 y las menores de leptina. Se concluye que KISS-10 evoca un aumento de LH en becerras de 4 a 11 meses, cuya magnitud de respuesta se asocia con la edad, con el incremento en sangre periférica de IGF-I y E2 y con la disminución de leptina sérica; en contraste, la respuesta de GH y FSH a KISS-10 no es afectada por la edad ni por las variaciones en IGF-I, E2 y leptina

Spectrometer and scanner with optofluidic configuration

We present a spectrometer and scanner based on optofluidic configurations. The main optical component of the spectrometer is a compound optical element consisting of an optofluidic lens and standard blazed diffraction grating. The spectrum size can be changed by filling the lens cavity with different liquids. The scanner comprises two hollow 45? angle prisms oriented at 90? to each other. By changing the liquid inside the prisms, two-dimensional light beam scanning can be performed. � 2013 Optical Society of America

Optofluidic spectrometer and beam aligner

Here we present two optofluidic configurations: a spectrometer and a beam aligner. The spectrometer has a compound element that consists of an optofluidic lens and a relief blazed diffraction grating. When light traverses the two optical elements it is focused and diffracted. At the focal length a spectrum is present. This spectrum can be collected by a CCD and information sent to a computer for analysis. Regarding the beam aligner it is made with two hollow prisms oriented 90� to each other. By changing the liquid inside the prisms an X-Y movement can be performed to align the beam. � 2013 Copyright SPIE

Fertilizer Source in Biomass Production and Quality of Essential Oils of Thyme (Thymus vulgaris L.)

Aims: The goal of this study was performed in order to test the effect of the source of crop fertilization and harvest days in the production of biomass and measure the qualitative and quantitative properties of the principal components of the essential oil of thyme. Study Design: A randomized complete block experimental design with five replications and a factorial arrangement was used. Place and Duration of Study: The experiment was at the Colegio de Postgraduados, Campus Montecillo (Texcoco, Mexico), during the 2007 spring-summer season. Methodology: We included three harvests at 60, 90 and 120 days after transplantation. The organic fertilization was with applications of humic acid in the irrigation and by adding a liquid fertilizer combined with biosynthetic amino acids. Steiner solution at 75% concentration was used for the inorganic fertilization as mineral treatment. We evaluated plant height, fresh and dry biomass of the plant, and main stem diameter. Essential oils were extracted using steam distillation of water. The concentration (µg/mL) of thymol and carvacrol was determined. Quantitative and qualitative comparisons were carried out by thin layer chromatography (TLC) and gas chromatography-mass spectrometry (GC-MS). Results: The results show that inorganic fertilization increased plant height (PH) by 36.8%, fresh shoot biomass (FSB) by 72.19%, fresh root biomass (FRB) by 59.27%, stem diameter (SD) by 12.15%, and dry shoot biomass (DSB) and dry root biomass (DRB) by 69.85% and 68.15%, respectively. Days to harvest (DH) influenced positively (p=.05) the evaluated morphological characters but they did not show differences in the total yield of essential oil. Conclusion: Our data show that fertilizer source modifies fresh and dry biomass production in thyme plants. The total yield of essential oils in thyme was not affected by days to harvest and fertilizer source. However, essential oil quality was higher in the mineral treatment at 90 DH due to the content of thymol and carvacrol in the extract.Objetivos: El objetivo de este estudio se realizó para probar el efecto de la fuente de fertilización de los cultivos y los días de cosecha en la producción de biomasa y medir las propiedades cualitativas y cuantitativas de los componentes principales del aceite esencial de tomillo. Diseño del estudio: Se utilizó un diseño experimental de bloques completos al azar con cinco repeticiones y un arreglo factorial. Lugar y Duración del Estudio: El experimento fue en el Colegio de Postgraduados, Campus Montecillo (Texcoco, México), durante la temporada primavera-verano 2007. Metodología: Se incluyeron tres cosechas a los 60, 90 y 120 días después del trasplante. La fertilización orgánica fue con aplicaciones de ácido húmico en el riego y mediante la adición de un fertilizante líquido combinado con aminoácidos biosintéticos. Se utilizó solución de Steiner a una concentración del 75% para la fertilización inorgánica como tratamiento mineral. Se evaluaron la altura de las plantas, la biomasa fresca y seca de la planta y el diámetro del tallo principal. Los aceites esenciales se extrajeron mediante destilación con vapor de agua. Se determinó la concentración (μg / ml) de timol y carvacrol. Las comparaciones cuantitativas y cualitativas se realizaron mediante cromatografía en capa fina (TLC) y cromatografía de gases-espectrometría de masas (GC-MS). Resultados: Los resultados muestran que la fertilización inorgánica aumentó la altura de la planta (PH) en un 36,8%, la biomasa fresca de los brotes (FSB) en un 72,19%, la biomasa de raíces frescas (FRB) en un 59,27%, el diámetro del tallo en un 12,15% Biomasa (DSB) y biomasa de raíz seca (DRB) en un 69,85% y un 68,15%, respectivamente. Los días de cosecha (DH) influyeron positivamente (p = 0,05) los caracteres morfológicos evaluados pero no mostraron diferencias en el rendimiento total de aceite esencial. Conclusión: Nuestros datos muestran que la fuente de fertilizante modifica la producción de biomasa fresca y seca en las plantas de tomillo. El rendimiento total de los aceites esenciales en el tomillo no se vio afectado por los días de la cosecha y la fuente de fertilizantes. Sin embargo, la calidad del aceite esencial fue mayor en el tratamiento mineral a 90 DH debido al contenido de timol y carvacrol en el extracto

Optofluidic variable focus lenses

Here we propose optofluidic spherical microlenses that can change their focal distance by varying the refractive index of the liquid that composes them. These lenses are fabricated in the bulk of a polymeric mixture. Results of a characterization study of the profile of the lenses, the image forming capability, and the behavior of the focal distance as a function of the refractive index are presented. Ionic liquids are suggested as a source of liquids useful for fabricating this type of lens. © 2009 Optical Society of America

Microlenses made with emulsion techniques

We present a method to make liquid lenses. It is based on the microfluidic method to make emulsions. An emulsion is a mixture of two immiscible liquids, where one liquid (the dispersed phase) is dispersed in the form of small droplets in another liquid that forms a continuous phase. The presence of a surfactant is necessary for the long term stability of emulsions. To make liquid lenses we have used capillaries. Through them we inject some microliters of a liquid. The result is that a spherical micro-lens is formed. These lenses can focus light or form images. We have tested the lenses through image forming techniques and compared the results with the ones given by an optical design program. � 2010 SPIE

Optofluidic compound microlenses made by emulsion techniques

Here we present a new method to make liquid lenses. It is based on the microfluidics method and involves the preparation of emulsions one drop at a time. Tests of lenses by image formation are presented. Experimental results are compared with results of an optical design program. We also present a new type of lens that we call a Compound Lens which consists of two spherical lenses, one inside the other. © 2010 Optical Society of America

Ingestión of chemical substances in gullet, analysis of the early and delayed complicaciones, in the handling of the same; a revisión of 70 cases [Ingestión de Sustancias Químicas en Esífago, Análisis de las complicaciones tempranas y tardías, en el manejo de los mismos; una revisión de 70 casos]

Here we present a new method to make liquid lenses. It is based on the microfluidics method and involves the preparation of emulsions one drop at a time. Tests of lenses by image formation are presented. Experimental results are compared with results of an optical design program. We also present a new type of lens that we call a Compound Lens which consists of two spherical lenses, one inside the other. " 2010 Optical Society of America.",,,,,,"10.1364/OE.18.018703",,,"http://hdl.handle.net/20.500.12104/43406","http://www.scopus.com/inward/record.url?eid=2-s2.0-77956373183&partnerID=40&md5=b53ed18525c975b7ee2e52eddefcde34",,,,,,"18",,"Optics Express",,"1870