Acoustically Levitated Whispering-Gallery Mode Microlasers

Acoustic levitation has become a crucial technique for contactless manipulation in several fields, particularly in biological applications. However, its application in the photonics field remains largely unexplored. In this study, we implement an affordable and innovative phased-array levitator that enables stable trapping in the air of micrometer dye-doped droplets, thereby enabling the creation of microlasers. For the first time, this paper presents a detailed performance of the levitated microlaser cavity, supported by theoretical analysis concerning the hybrid technology based on the combination of whispering-gallery modes and acoustic fields. The pressure field distribution inside the acoustic cavity is numerically solved and qualitatively matched with the schlieren deflectometry technique. The optical lasing features of the levitated microlasers are highly comparable with those devices based On-a-Chip registering maximum Q-factors of ~ 105, and minimum lasing thresholds ~ 150 nJ cm−2. The emission comb is explained as a sum of multiple individual-supported whispering-gallery modes. The use of novel touchless micrometric lasers, produced with an acoustic levitator brings new technological opportunities based on photonic-acoustic technological platforms

Visualization and 3D Reconstruction of Flame Cells of Taenia solium (Cestoda)

BACKGROUND: Flame cells are the terminal cells of protonephridial systems, which are part of the excretory systems of invertebrates. Although the knowledge of their biological role is incomplete, there is a consensus that these cells perform excretion/secretion activities. It has been suggested that the flame cells participate in the maintenance of the osmotic environment that the cestodes require to live inside their hosts. In live Platyhelminthes, by light microscopy, the cells appear beating their flames rapidly and, at the ultrastructural, the cells have a large body enclosing a tuft of cilia. Few studies have been performed to define the localization of the cytoskeletal proteins of these cells, and it is unclear how these proteins are involved in cell function. METHODOLOGY/PRINCIPAL FINDINGS: Parasites of two different developmental stages of T. solium were used: cysticerci recovered from naturally infected pigs and intestinal adults obtained from immunosuppressed and experimentally infected golden hamsters. Hamsters were fed viable cysticerci to recover adult parasites after one month of infection. In the present studies focusing on flame cells of cysticerci tissues was performed. Using several methods such as video, confocal and electron microscopy, in addition to computational analysis for reconstruction and modeling, we have provided a 3D visual rendition of the cytoskeletal architecture of Taenia solium flame cells. CONCLUSIONS/SIGNIFICANCE: We consider that visual representations of cells open a new way for understanding the role of these cells in the excretory systems of Platyhelminths. After reconstruction, the observation of high resolution 3D images allowed for virtual observation of the interior composition of cells. A combination of microscopic images, computational reconstructions and 3D modeling of cells appears to be useful for inferring the cellular dynamics of the flame cell cytoskeleton

Optimal fertilization dose in castor bean (Ricinus communis L.) using partial budgets analysis

Objective: To determine the economically adequate fertilization dose for a castor bean (Ricinus communis L.) crop that improves the producer's benefits using the partial budgeting technique. Design / methodology / approach: The experiment was established at a site located 500 m from the Centro de Chiapas experimental field, with an altitude of 800 m. Two production factors were studied: nitrogen (40, 60, and 80) and phosphorus (20, 40, and 60) with three levels each. The treatments had nine combinations in a randomized complete block experimental design and four replications. Phenological and morphological variables, seed yield, and variable costs economic components were evaluated as a response. Results: With the average yields the obtained net benefits were determined; an adjustment of the benefits was made, and its dominance was determined. Four experiments were dominated, and five showed favorable profits for the producer. The 80-60-00 formulation had a return rate (RR) of 23 %. Conclusions: The 40-20-00, 40-40-00, 40-60-00, 80-40-00 and 80-60-00 formulations were dominant. The 80-60-00 formulation reported the highest RR, an increase in variable cost of US$9.64, like other doses of lower costs and benefits. For this dose, the net benefits increase was us$ 222.61

Desarrollo de una Nueva Solución Compacta a la Cinemática de Manipuladores Robóticos basada en Cuaterniones Duales

ResumenEste trabajo presenta una nueva solución compacta basada en cuaterniones duales para el desarrollo de la cinemática de manipuladores robóticos. Se plantea el desarrollo de una herramienta en forma completa para poder observar claramente su correlación con el método de las matrices de transformación homogénea derivadas a partir de los parámetros de Denavit-Hartenberg. Se proponen herramientas para simplificar el uso de los cuaterniones duales para la obtención del modelo cinemático de mecanismos de cadena abierta definiendo la regla de la cadena aplicada a estos. Finalmente se ilustra su aplicación a un par de casos de estudio

Influence of tannic acid concentration on the physicochemical characteristics of saliva of spider monkeys (Ateles geoffroyi)

Tannins are a chemical defense mechanism of plants consumed by herbivores. Variations in salivary physicochemical characteristics such as pH, total protein concentration (TP), and presence of proline-rich proteins (PRPs) in animals have been reported as a mechanism to protect the oral cavity when consuming food with variations in pH and tannins. Variations in salivary physiochemistry as adaptations for consuming tannin-rich foods have been found in omnivorous and folivorous primates, but have not yet been reported in frugivorous species such as spider monkeys. We therefore assessed changes in pH using test strips, TP concentration by measuring absorbance at 595 nm in a spectrophotometer and salivary PRPs using the SDS-PAGE electrophoresis technique in the saliva of nine captive spider monkeys in response to the consumption of solutions with different concentrations of tannic acid. The results showed variations in pH, TP concentration and the presence and variation of possible salivary PRPs associated with tannic acid concentration. These findings suggest that spider monkeys may tailor their salivary physicochemical characteristics in response to the ingestion of potentially toxic compounds.Funding agencies: Consejo Nacional de Ciencia y Tecnología CONACYT (726258)</p

Análisis conceptual del aprendizaje observacional y la imitación.

En este trabajo se analizaron los conceptos que se han presentado para explicar lo que ocurre en situaciones de aprendizaje social, aprendizaje observacional e imitación. Con el uso del modelo de desarrollo del comportamiento presentado por Hogan (1994b) para organizarlos se señaló que los conceptos analizados se refieren a diferentes fuentes de control del estímulo. Se revisaron, asimismo, los factores asociativos que determinan tanto el aprendizaje social como el cambio de valencia y la potenciación; se indicó, también, la relación del aprendizaje social con la disposición de la ocasión. Se sugiere que estos tres términos equivalen a un paradigma de discriminación condicional

A multicenter study on the prevalence and spectrum of mutations in the otoferlin gene (OTOF) in subjects with nonsyndromic hearing impairment and auditory neuropathy

Autosomal recessive nonsyndromic hearing impairment (NSHI) is a heterogeneous condition, for which 53 genetic loci have been reported, and 29 genes have been identified to date. One of these, OTOF, encodes otoferlin, a membrane-anchored calcium-binding protein that plays a role in the exocytosis of synaptic vesicles at the auditory inner hair cell ribbon synapse. We have investigated the prevalence and spectrum of deafness-causing mutations in the OTOF gene. Cohorts of 708 Spanish, 83 Colombian, and 30 Argentinean unrelated subjects with autosomal recessive NSHI were screened for the common p.Gln829X mutation. In compound heterozygotes, the second mutant allele was identified by DNA sequencing. In total, 23 Spanish, two Colombian and two Argentinean subjects were shown to carry two mutant alleles of OTOF. Of these, one Colombian and 13 Spanish subjects presented with auditory neuropathy. In addition, a cohort of 20 unrelated subjects with a diagnosis of auditory neuropathy, from several countries, was screened for mutations in OTOF by DNA sequencing. A total of 11 of these subjects were shown to carry two mutant alleles of OTOF. In total, 18 pathogenic and four neutral novel alleles of the OTOF gene were identified. Haplotype analysis for markers close to OTOF suggests a common founder for the novel c.2905_2923delinsCTCCGAGCGCA mutation, frequently found in Argentina. Our results confirm that mutation of the OTOF gene correlates with a phenotype of prelingual, profound NSHI, and indicate that OTOF mutations are a major cause of inherited auditory neuropathy

. 61 (2005) mayo-agosto. Historias. Revista de la Dirección de Estudios Históricos

- La historia de la Exposición de la Armería por Walt Kuhn. - Las ideas sobre la felicidad en Rusia, siglos XVII-XVIII por O. E. Kosheleva. - El ejemplo como categoría política por Javier Gomá Lanzón. - Los límites de “lo público”. Conflictos por el uso del caudal del río Magdalena en el valle de México durante el Porfiriato por Mario Barbosa Cruz. - La correspondencia de Joaquín García Icazbalceta con Manuel Remón Zarco del Valle por Rodrigo Martínez Baracs. - La geografía como disciplina científica. Por un reencuentro con la historia por Eulalia Ribera Carbó. - “Indígenas, mezclados y blancos”, según el Censo General de Habitantes de 1921 por Dolores Pla Brugat. - Holger Cahill y el inje-inje. La historia del primitivismo modernista por Alan Moore. - Despotismo virreinal en el siglo XVIII: Bando del marqués de Croix del 8 de diciembre de 1769 por Esteban Sánchez de Tagle. - José Justo Gómez de la Cortina: el personaje, el escritor y el periodista por Mariana Riva Palacio Quintero. - Tlalocan purépecha por Rodrigo Martínez Baracs. - Melancólicos y endemoniados en Nueva España por Antonio Rubial García. - González Obregón revisitado por Marcela Dávalos. – Crestomanía por José Mariano Leyva