Noninvasive imaging of three-dimensional micro and nanostructures by topological methods

We present topological derivative and energy based procedures for the imaging of micro and nano structures using one beam of visible light of a single wavelength. Objects with diameters as small as 10 nm can be located and their position tracked with nanometer precision. Multiple objects dis-tributed either on planes perpendicular to the incidence direction or along axial lines in the incidence direction are distinguishable. More precisely, the shape and size of plane sections perpendicular to the incidence direction can be clearly determined, even for asymmetric and nonconvex scatterers. Axial resolution improves as the size of the objects decreases. Initial reconstructions may proceed by gluing together two-dimensional horizontal slices between axial peaks or by locating objects at three-dimensional peaks of topological energies, depending on the effective wavenumber. Below a threshold size, topological derivative based iterative schemes improve initial predictions of the lo-cation, size, and shape of objects by postprocessing fixed measured data. For larger sizes, tracking the peaks of topological energy fields that average information from additional incident light beams seems to be more effective

Igniting homogeneous nucleation

Transient homogeneous nucleation is studied in the limit of large critical sizes. Starting from pure monomers, three eras of transient nucleation are characterized in the classic Becker-D\"oring kinetic equations with two different models of discrete diffusivity: the classic Turnbull-Fisher formula and an expression describing thermally driven growth of the nucleus. The latter diffusivity yields time lags for nucleation which are much closer to values measured in experiments with disilicate glasses. After an initial stage in which the number of monomers decreases, many clusters of small size are produced and a continuous size distribution is created. During the second era, nucleii are increasing steadily in size in such a way that their distribution appears as a wave front advancing towards the critical size for steady nucleation. The nucleation rate at critical size is negligible during this era. After the wave front reaches critical size, it ignites the creation of supercritical clusters at a rate that increases monotonically until its steady value is reached. Analytical formulas for the transient nucleation rate and the time lag are obtained that improve classical ones and compare very well with direct numerical solutions.Comment: 32 pages, 6 figures, to appear in Phys. Rev.

Nota sobre las características estructurales de la zona de "Cueto Negro" (Cordillera Cantábrica)

Se citan algunos datos estructurales respecto a la zona comprendida entre los puertos Pajares y La Cubilla (Cordillera Cantábrica). Se destaca la presencia de una ventana tectónica, en la zona de Cueto negro, relacionada con la unidad cabalgante de Bodón, ampliamente replegada. Estos elementos se integran dentro del haz de estructuras que caracterizan el "arco medio" de la Rodilla Astúrica (Cordillera Cantábrica, España)

Circadian Rhythm Alteration and Metabolic Syndrome

There is growing scientific evidence that connects circadian rhythm abnormalities with cardiovascular risk factors. Due to their work schedules, shift workers are exposed to changes in their circadian rhythm that are associated with metabolic syndrome (MS). Aim: To determine the relationship between shift work and metabolic syndrome. Methodology: This is a cross-sectional observational study. The sample included 300 adult volunteers, health workers of a public hospital in the city of Riobamba, Ecuador. The diagnosis of MS was made based on the criteria bythe Adult Treatment Panel III (ATP III). In addition, sleep quality was assessed through the Pittsburg sleep quality index. Cluster analysis of K-means was used to identify representative groups. In addition, chi-squared test and ANOVA were used to determine the association between variables. Results: Three conglomerates based on age and sex were established, which were numbered consecutively 1, 2 and 3. Conglomerate 1 had a statistically higher percentage of people who worked in shifts, suffered MS and had worse sleep quality than the other two conglomerates. In conclusión, shift work is related to the risk of suffering from MS and poor quality of sleep. Keywords: shift work, metabolic syndrome, sleep quality, k medias clusters. Resumen Introducción: La evidencia creciente conecta las alteraciones del ritmo circadiano con factores de riesgo cardiovascular. Los trabajadores por turnos debido a sus horarios de trabajo están expuestos a alteraciones de su ritmo circadiano que se asocian a síndrome metabólico (SM). Objetivo: Determinar la relación entre trabajo por turnos y síndrome metabólico. Metodología: Estudio observacional transversal. La muestra incluyó 300 voluntarios adultos, empleados sanitarios de un hospital público de la ciudad de Riobamba, Ecuador. El diagnóstico de SM se realizó con base en los criterios del Adult Treatment Panel III (ATP III). Además, se evaluó la calidad del sueño a través del índice de la calidad de sueño de Pittsburg. Se utilizó el análisis de clúster de K medias para identificar grupos representativos, además Chi2 y ANOVA para determinar asociación entre las variables. Resultados: Se establecieron tres clusters basados en edad y sexo, los que fueron numerados de forma consecutiva 1, 2 y 3. El cluster 1 tuvo un porcentaje estadísticamente más alto de personas que trabajaban por turnos, sufrían SM y que presentaron peor calidad de sueño que los otros dos clusters. Conclusiones: El trabajo por turnos se relaciona con el riesgo de sufrir SM y mala calidad de sueño. Palabras clave: trabajo por turnos, síndrome metabólico, calidad del sueño, análisis de k medias

Dust temperature and CO-to-H2 conversion factor variations in the SFR-M* plane

Deep Herschel imaging and 12CO(2-1) line luminosities from the IRAM PdBI are combined for a sample of 17 galaxies at z>1 from the GOODS-N field. The sample includes galaxies both on and above the main sequence (MS) traced by star-forming galaxies in the SFR-M* plane. The far-infrared data are used to derive dust masses, Mdust. Combined with an empirical prescription for the dependence of the gas-to-dust ratio on metallicity (GDR), the CO luminosities and Mdust values are used to derive for each galaxy the CO-to-H2 conversion factor, alpha_co. Like in the local Universe, the value of alpha_co is a factor of ~5 smaller in starbursts compared to normal star-forming galaxies (SFGs). We also uncover a relation between alpha_co and dust temperature (Tdust; alpha_co decreasing with increasing Tdust) as obtained from modified blackbody fits to the far-infrared data. While the absolute normalization of the alpha_co(Tdust) relation is uncertain, the global trend is robust against possible systematic biases in the determination of Mdust, GDR or metallicity. Although we cannot formally distinguish between a step and a smooth evolution of alpha_co with the dust temperature, we can conclude that in galaxies of near-solar metallicity, a critical value of Tdust=30K can be used to determine whether the appropriate alpha_co is closer to the starburst value (1.0 Msun(K kms pc^2)^-1, if Tdust>30K) or closer to the Galactic value (4.35 Msun (K kms pc^2)^-1, if Tdust<30K). This indicator has the great advantage of being less subjective than visual morphological classifications of mergers/SFGs, which can be difficult at high z because of the clumpy nature of SFGs. In the absence of far-infrared data, the offset of a galaxy from the main sequence (i.e., log[SSFR(galaxy)/SSFR_MS(M*,z)]) can be used to identify galaxies requiring the use of an alpha_co conversion factor lower than the Galactic value.Comment: Accepted for publication in Astronomy and Astrophysics (A&A); 15 pages, 6 figures; V2: updated reference lis

Β-carotene, iron and zinc content, effect of storage and type of cooking in sweet potato (Ipomoea batatas L) genotypes

El camote (Ipomoea batatas L) es el principal componente en la dieta de millones de personas que viven en países tropicales, y un mejoramiento en el contenido de â-caroteno podría incrementar el suministro de vitamina A para satisfacer la mayor parte de las necesidades diarias de la gente. En el presente estudio, el contenido de â-caroteno (BC), hierro (Fe) y zinc (Zn) fueron determinados en 25 genotipos de camote provenientes de las localidades de La Molina y San Ramón (Perú). Así mismo, los cambios en el contenido de BC en siete genotipos de camote fueron investigados usando diferentes métodos de cocción y tiempos de almacenamiento. El contenido de BC fue medido vía absorbancia a 450 nm e identificado a través del HPLC y el contenido de Fe y Zn fueron determinados a través de técnicas de ICP-OES. Los resultados muestran variación significativa entre genotipo, ambiente y en la interacción genotipo-ambiente. La concentración de BC en las raíces de camote recién cosechado varió entre 7.62 y 18.93 mg/100 g en peso fresco (PF). El contenido de hierro presentó un rango de 0.40 – 0.96 mg/100 g PF y el contenido de zinc presentó un rango de 0.25 – 0.51 mg/100 mg PF. Los genotipos 440442 y 440518 presentaron los niveles más altos de BC en los dos ambientes. Diferencias en el contenido de BC fueron encontrados entre los métodos de cocción y los tiempos de almacenamiento. La concentración de BC de las raíces cocidas por ebullición (15.15 mg/100 g PF) fue mayor que las raíces cocidas por horneado (14.29 mg/100 g PF); sin embargo, no hubo diferencias entre los genotipos 440442 y 420081 por efecto del método de cocción. Asimismo, el contenido de BC se incrementó durante el tiempo de almacenamiento, donde el genotipo 440442 presentó los mayores niveles de BC durante el tiempo de almacenamiento, mientras que los genotipos 440413 y 440513 no presentaron cambios significativos.Sweet potato (Ipomoea batatas L) is the main component in the diet of millions of people living in tropical countries, and an improvement in β-carotene content could increase the supply of vitamin A to meet a greater part of the daily requirements of people. In the present study, the content of β-carotene (BC), iron (Fe) and zinc (Zn) were determined in 25 genotypes of sweet potato from two localities: La Molina and SanRamón. Furthermore, the changes in BC content in seven sweet potato genotypes were investigated using different cooking methods and storage times. The content of BC was measured via absorbance at 450 nm and identified through HPLC while Fe and Zn content were determined through ICP-OES techniques. The results show significant variation between genotype, environment and in the genotype-environment interaction. BC content in freshly harvested raw root ranged from 7.62 to 18.93 mg /100 g in fresh weight (PF), iron content ranged from 0.40 to 0.9 6mg/100 g PF and the zinc content ranged from 0.25 to 0.51 mg/100 mg PF. Genotypes 440442 and 440518 showed the highest levels of BC in bothlocalities. Differences in BC content were found among cooking methods and storage times. BC concentration in boiled roots (15.15 mg/100 g PF) evaluated was higher than in baked roots (14.29 mg/100 g PF); however, without differences between genotypes 440442 and 420081 due to the cooking methods. BC content of root increased with storage time, where genotype 440442 showed the highest levels of BC during storage time, while genotypes 440413 and 440513 did not differ during storage time

Mechanical properties of double-layer and graded composite coatings of YSZ obtained by atmospheric plasma spraying

Double-layer and graded composite coatings of yttria-stabilized zirconia were sprayed on metallic substrates by atmospheric plasma spray. The coating architecture was built up by combining two different feedstocks: one micro- and one nanostructured. Microstructural features and mechanical properties (hardness and elastic modulus) of the coatings were determined by FE-SEM microscopy and nanoindentation technique, respectively. Additional adherence and scratch tests were carried out in order to assess the failure mechanisms occurring between the layers comprising the composites. Microstructural inspection of the coatings confirms the two-zone microstructure. This bimodal microstructure which is exclusive of the layer obtained from the nanostructured feedstock negatively affects the mechanical properties of the whole composite. Nanoindentation tests suitably reproduce the evolution of mechanical properties through coatings thickness on the basis of the position and/or amount of nanostructured feedstock used in the depositing layer. Adhesion and scratch tests show the negative effect on the coating adhesion of layer obtained from the nanostructured feedstock when this layer is deposited on the bond coat. Thus, the poor integrity of this layer results in lower normal stresses required to delaminate the coating in the adhesion test as well as minor critical load registered by using the scratch test.This work has been supported by the Spanish Ministry of Science and Innovation (Project MAT2012-38364-C03) and co-funded by ERDF (European Regional Development Funds).Carpio-Cobo, P.; Rayón Encinas, E.; Salvador Moya, MD.; Lusvarghi, L.; Sanchez, E. (2016). Mechanical properties of double-layer and graded composite coatings of YSZ obtained by atmospheric plasma spraying. 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Deriving a multivariate CO-to-H2_2 conversion function using the [CII]/CO(1-0) ratio and its application to molecular gas scaling relations

We present Herschel PACS observations of the [CII] 158 micron emission line in a sample of 24 intermediate mass (9<logM$_\ast$/M$_\odot$<10) and low metallicity (0.4< Z/Z$_\odot$<1.0) galaxies from the xCOLD GASS survey. Combining them with IRAM CO(1-0) measurements, we establish scaling relations between integrated and molecular region [CII]/CO(1-0) luminosity ratios as a function of integrated galaxy properties. A Bayesian analysis reveals that only two parameters, metallicity and offset from the star formation main sequence, $\Delta$MS, are needed to quantify variations in the luminosity ratio; metallicity describes the total dust content available to shield CO from UV radiation, while $\Delta$MS describes the strength of this radiation field. We connect the [CII]/CO luminosity ratio to the CO-to-H$_2$ conversion factor and find a multivariate conversion function $\alpha_{CO}$, which can be used up to z~2.5. This function depends primarily on metallicity, with a second order dependence on $\Delta$MS. We apply this to the full xCOLD GASS and PHIBSS1 surveys and investigate molecular gas scaling relations. We find a flattening of the relation between gas mass fraction and stellar mass at logM$_\ast$/M$_\odot$<10. While the molecular gas depletion time varies with sSFR, it is mostly independent of mass, indicating that the low L$_{CO}$/SFR ratios long observed in low mass galaxies are entirely due to photodissociation of CO, and not to an enhanced star formation efficiency.Comment: Submitted to MNRAS, this version after referee comments. 21 page

A genome-wide association analysis for body, udder, and leg conformation traits recorded in Murciano-Granadina goats

Morphological traits are of great importance to dairy goat production given their effect on phenotypes of economic interest. However, their underlying genomic architecture has not yet been extensively characterized. Herein, we aimed to identify genomic regions associated with body, udder, and leg conformation traits recorded in 825 Murciano-Granadina goats. We genotyped this resource population using the GoatSNP50 BeadChip (Illumina Inc., San Diego, CA) and performed genome-wide association analyses using the GEMMA software. We found 2 genome-wide significant associations between markers rs268273468 [Capra hircus (CHI) 16:69617700] and rs268249346 (CHI 28:18321523) and medial suspensory ligament. In contrast, we did not detect any genome-wide significant associations for body and leg traits. Moreover, we found 12, 19, and 7 chromosome-wide significant associations for udder, body, and leg traits, respectively. Comparison of our data with previous studies revealed a low level of positional concordance between regions associated with morphological traits. In addition to technical factors, this lack of concordance could be due to a substantial level of genetic heterogeneity among breeds or to the strong polygenic background of morphological traits, which makes it difficult to detect genetic factors that have small phenotypic effects