Tone Reproduction of Small-Scale Images Using Lithographic Film Under Infectious and Noninfectious Developmental Conditions

The tone reproduction curve of small-scale images on KODALITH film developed with KODALITH Super Developer were obtained by microdensitometry using a sinusoidal target of 64 percent modulation as a sensitometric tablet to produce images at spatial frequencies corresponding to screen rulings of 9 to 375 lines/inch. A similar series of exposures was processed with addition of sulfite to the developer to give essentially noninfectious development. Speed and contrast with KODALITH developer increased with spatial frequency; speed increased continuously by a small factor and contrast passed through a maximum (80 percent greater than for large area image) at a spatial frequency between 3/8 and 3 cycles/millimeter then decreased with increasing spatial frequency back to the large image level. The contrast and speed for noninfectious development were essentially independent of spatial frequency. The change in speed and contrast for both the infectious and noninfectious development were relatively independent of exposure level

Export Growth and Factor Market Competition: Theory and Evidence

Empirical evidence suggests that sectoral export growth decreases exporters' survival probability, whereas non-exporters are unaffected. Models with firm heterogeneity in total factor productivity predict the opposite. To solve this puzzle, we develop a two-factor framework where firms differ in factor shares. In this model, export growth increases competition for the factor used intensively by exporters, eliminating some of them, while non-exporters benefit. Our empirical analysis shows that the forces highlighted in the model drive the firm selection experienced by the Chilean manufacturing sector, suggesting that heterogeneity in factor shares is crucial to understand how firms react to trade liberalization.Firm Dynamics, Two-factor Trade Model, Firm Heterogeneity in Factor Input Shares, Chile, Manufacturing Industry

Using Scratch to Teach Undergraduate Students' Skills on Artificial Intelligence

This paper presents a educational workshop in Scratch that is proposed for the active participation of undergraduate students in contexts of Artificial Intelligence. The main objective of the activity is to demystify the complexity of Artificial Intelligence and its algorithms. For this purpose, students must realize simple exercises of clustering and two neural networks, in Scratch. The detailed methodology to get that is presented in the article.Comment: 6 pages, 7 figures, workshop presentatio

Export Growth and Factor Market Competition: Theory and Evidence

Empirical evidence suggests that sectoral export growth decreases exporters\' survival probability, whereas non{exporters are unaffected. Models with firm heterogeneity in total factor productivity predict the opposite. To solve this puzzle, we develop a two-factor framework where firms differ in factor shares. In this model, export growth increases competition for the factor used intensively by exporters, eliminating some of them, while non-exporters benefit. Our empirical analysis shows that the forces highlighted in the model drive the firm selection experienced by the Chilean manufacturing sector, suggesting that heterogeneity in factor shares is crucial to understand how firms react to trade liberalization.Firm Dynamics, Two-Factor Trade Model, Firm Heterogeneity in Factor Shares, Chile, Manufacturing Industry

Empleo del visualizador gráfico Jmol en las clases de simetría molecular

El presente trabajo divulga la innovación educativa que se ha desarrollado en la asignatura Química Inorgánica III (QU0924) del tercer curso del Grado en Química en el curso académico 2013/2014, de la Universitat Jaume I (Castellón, España). El objetivo fundamental de nuestro proyecto era dotar a los estudiantes de material didáctico interactivo y diferente, para un mejor aprendizaje de conceptos fundamentales de simetría molecular. En particular, los estudiantes fueron introducidos en el manejo de la interfaz gráfica Jmol, con la que se pueden construir y visualizar modelos tridimensionales.This article reports the educational innovation that has been implemented in the subject Inorganic Chemistry III (QU0924) of the third year of the Chemistry Degree, during the academic year 2013/2014 at the Universitat Jaume I (Castellón, Spain). The main goal of our project was to provide the students with interactive and new didactic material, for a better understanding of the fundamental concepts of molecular symmetry. In particular, the students were introduced to the use of the Jmol graphic interface, very useful for constructing and visualize three-dimensional models

The relationship between developmental stability, Ggenomic diversity and environmental stress in two cetacean species:: the Harbour Porpoise (Phocoenaphocoena) and The Bottlenose Dolphin (Tursiops truncatusl)

The relationship between developmental stability, genomic diversity and environmental stress in three eastern North Atlantic populations of the harbour porpoise {Phocoena phocoena), and in two populations of the western North Atlantic and one from the Gulf of California of the bottlenose dolphin {Tursiops truncatus) was investigated. In addition, the population structure for the two species from the study areas mentioned was also assessed. Population structure was determined using discriminant function analysis for morphological characters and a Bayesian analysis for microsatellite loci. Consistency of the results was assessed with pairwise comparisons between populations using two indices of population differentiation (F(_st) and Rho(_st)). For the harbour porpoises classification was made into three putative populations: Norwegian, British and Danish. For the bottlenose dolphin significant differentiation was found for the three populations studied. Population differentiation between the two western North Atlantic parapatric populations was the highest among the pairwise comparisons. This result highlights the importance of resource specialisation of bottlenose dolphins in causing population structure for parapatric populations. Developmental stability was assessed by fluctuating asymmetry (FA) measured on morphological traits. Genomic diversity was determined by five indices (mean cf, scaled mean cF, multilocus individual heterozygosity, standardised heterozygosity and internal relatedness). Environmental stress was assessed by the concentration of chemical pollutants in tissues, and from the literature published for chemical pollutants, by-catch rate, parasite load and mean surface ocean temperature. Significant relationships between FA and the indices of genomic diversity were found. The Norwegian population of harbour porpoises and the coastal population of the western North Atlantic of bottlenose dolphin showed the highest level of FA. Both populations also showed the least genetically diverse animals. However, no clarity was obtained in respect of the relationship between FA and environmental stress. British and Norwegian harbour porpoises did not show significant correlations between the concentration of several chemical pollutants in tissues and FA. In addition, the Norwegian population of harbour porpoise inhabits the least impacted areas in respect to the concentration of chemical pollutants in tissues, parasite load and by-catch rates. Environmental stress was difficult to assess on the bottlenose dolphins populations due to the scarcity of data. These results show the influence of genetic diversity on the disruption of developmental stability and they also show the importance of conservation practices in maintaining genetic diversity as an important factor for the subsistence of natural populations

Ultrafast Synthesis and Coating of High Quality β-NaYF4:Yb3+,Ln3+ Short Nanorods

An ultrafast route to prepare up-converting single β-phase NaYF4:Yb3+,Ln3+ (Ln: Er, Tm, or Tb) short nanorods (UCNRs) of high quality was developed. This new procedure affords reactive-surface nanorods that are easily coated by direct injection of suitable capping ligands. Thus highly crystalline nanorods with excellent UC fluorescence and good solvent-selective dispersion are obtained, which represents a significant advance in the field and enlarges their use for biomedical and other technological applications. Unlike other methodologies, the short reaction time provides a kinetic control over crystallization processes, and the β-phase and rod morphology is preserved regardless of the optically active Ln3+ ion. The UC emission was finely tuned by using the most popular Yb3+/Tm3+ and Yb3+/Er3+ pairs. More importantly, UCNRs doped with the unusual Yb3+/Tb3+ pair, with no ladder-like energy levels, provided a nice emission upon near-infrared excitation, which constitutes the first example of phonon-assisted cooperative sensitization to date in pure β-NaYF4 nanocrystals