Galactic Archaeology: Tracing the Milky Way's Formation and Evolution through Stellar Populations

Galactic archaeology represents a multidisciplinary approach aimed at unraveling the intricate history of the Milky Way galaxy through the study of its stellar populations. This abstract delves into the significance of galactic archaeology as a vital tool for understanding the formation and evolution of the Milky Way. By examining the distribution, kinematics, chemical compositions, and ages of stars within the galaxy, researchers gain insights into the dynamic processes that have shaped its structure over billions of years. Stellar populations serve as invaluable relics of past epochs, preserving clues about the conditions prevalent during their formation. The utilization of spectroscopic and photometric data has enabled the classification and analysis of stars, allowing astronomers to discern distinct populations and unveil their origin stories. Through these studies, the emergence of the Milky Way's various components, such as the thin and thick disk, halo, and bulge, becomes discernible.Comment: 6 pages, 3 figure

Effect of mash feed on swine intestinal microflora and non-specific immune response.

Pelleting of feed was recommended in the past to reduce the risk of introduction of Salmonella in swine herds. However it was shown more recently that consumption of pelleted feed was associated with an increased probability of seropositivity Furthermore, several studies showed that the prevalence of Salmonella is decreased when mash feed is used. The objective of this study was to evaluate the effect of mash feed as a pre-harvest intervention strategy to prevent Salmonella colonization, to mod1fy of intestinal microflora and to stimulate of the immune system in swine

An integrated approach for analysing and assessing the performance of virtual learning groups

Collaborative distance learning involves a variety of elements and factors that have to be considered and measured in order to analyse and assess group and individual performance more effectively and objectively. This paper presents an approach that integrates qualitative, social network analysis (SNA) and quantitative techniques for evaluating online collaborative learning interactions. Integration of various different data sources, tools and techniques provides a more complete and robust framework for group modelling and guarantees a more efficient evaluation of group effectiveness and individual competence. Our research relies on the analysis of a real, long-term, complex collaborative experience, which is initially evaluated in terms of principled criteria and a basic qualitative process. At the end of the experience, the coded student interactions are further analysed through the SNA technique to assess participatory aspects, identify the most effective groups and the most prominent actors. Finally, the approach is contrasted and completed through a statistical technique which sheds more light on the results obtained that far. The proposal draws a well-founded line toward the development of a principled framework for the monitoring and analysis of group interaction and group scaffolding which can be considered a major issue towards the actual application of the CSCL proposals to real classrooms.Peer ReviewedPostprint (author's final draft

Influence of levofloxacin and clarithromycin on the structure of DPPC monolayers

Research on lipid/drug interactions at the nanoscale underpins the emergence of synergistic mechanisms for topical drug administration. The structural understanding of bio-mimetic systems employing 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) as a lung surfactant model mixed with antibiotics, as well as their biophysical properties, is of critical importance to modulate the effectiveness of therapeutic agents released directly to the airways. In this paper, we investigate the structural details of the interaction between Levofloxacin, ‘a respiratory quinolone’, and the macrolide Clarithromycin, with DPPC monolayers at the air-water interface, using a combination of Brewster angle microscopy, polarization modulation-infrared reflection-adsorption spectroscopy (PM-IRRAS), surface pressure isotherms and neutron reflectometry (NR) to describe the structural details of this interaction. The results allowed association of changes in the π-A isotherm profile with changes in the molecular organization and the co-localization of the antibiotics within the lipid monolayer by NR measurements. Overall, both antibiotics are able to increase the thickness of the acyl tails in DPPC monolayers with a corresponding reduction in tail tilt as well as to interact with the phospholipid headgroups as shown by PM-IRRAS experiments. The effects on the DPPC monolayers are correlated with the physical-chemical properties of each antibiotic and dependent on its concentration

Technical performance and diagnostic utility of the new Elecsys (R) neuron-specific enolase enzyme immunoassay

This international multicenter study was designed to evaluate the technical performance of the new double-monoclonal, single-step Elecsys neuron-specific enolase (NSE) enzyme immunoassay (EIA) and to assess its utility as a sensitive and specific test for the diagnosis of small-cell lung cancer (SCLC). Intra and interassay coefficients of variation, determined in five control or serum specimens in six laboratories, ranged from 0.7 to 5.3 (interlaboratory median: 1.3%) and from 1.3 to 8.5 (interlaboratory median: 3.4%), respectively. Laboratory-to-laboratory comparability was excellent with respect to recovery and interassay coefficients of variation. The test was linear between 0.0 and 320 ng/ml (highest measured concentration). There was a significant correlation between NSE concentrations measured using the Elecsys NSE and the established Cobas Core NSE EIA II in all subjects (n=723) and in patients with lung cancer (n=333). However, NSE concentrations were systematically lower (approximately 9%) with the Elecsys NSE than with the comparison test. Based on a specificity of 95% in comparison with the group suffering from benign lung diseases (n=183), the cutoff value for the discrimination between malignant and benign conditions was set at 21.6 ng/ml. NSE was raised in 73.4% of SCLC patients (n=188) and was significantly higher (p<0.01) in extensive (87.8%) as opposed to limited disease (56.7%). NSE was also elevated in 16.0% of the cases with non-small cell lung cancer (NSCLC, n=374). It is concluded that the Elecsys NSE EIA is a reliable and accurate diagnostic procedure for the measurement of NSE in serum samples. The special merits of this new assay are the wide measuring range (according to manufacturers declaration up to 370 ng/ml) and a short incubation time of 18 min

Ensayos de biodegradabilidad anaerobia de efluentes cerveceros con lodo granular y lodo floculento

Desde comienzos de la década de los noventa la industria cervecera del país ha venido implementando tecnologías anaerobias, particularmente del tipo UASB (Upflow Anaerobic Sludge Blanket), para el tratamiento de las aguas residuales de sus plantas industriales en diferentes regiones del país. Por diferentes razones estas instalaciones están funcionando con algunas deficiencias, lo cual es motivo de preocupación tanto para el sector industrial como para las entidades de control. El presente artículo constituye la segunda parte de una investigación encaminada a establecer criterios para la selección y mejoramiento de lodos utilizados en estos sistemas. También se busca analizar la influencia de otros factores asociados como características del desecho, condiciones de operación y parámetros de diseño. El estudio se desarrolló en dos etapas, en las que se emplearon lodo granular y lodo floculento para evaluar la degradabilidad de los residuos líquidos de dos plantas de cerveceras. Igualmente, se incluyó el lodo propio de una de esas instalaciones.At the beginning of nineties the colombian beer industry begun the application of anaerobic technology for the treatment of their wastewater efluents throught different regions of the country. These treatment plants have not been working appropriately due to different factors, and are creating concern among the industrial sector and the water pollution control agencies. This work constitutes the second phase of a research project designed to establish a selection and improvement criteria of the sludges used in the systems. It also looks to analyze other associated factors such as: waste, characteristics, operation conditions and design parameters. The investigation was conducted in two phases using granular and floculent sludges. This method was used for determining the anaerobic biodegradability of wastewater from two industrial plants

Modelo liviano de medidas para evaluar la mejora de procesos de desarrollo de software MLM-PDS

Companies in software development in Colombia face a number of problems such as the construction of software in a artesian, empirical and disorganized way. Therefore, it is necessary for these companies to implement projects to improve their development processes, because ensure the quality of products, by improving their software processes, is a step that should give to be able to compete in the market. To implement process improvement models, it is not enough to say whether a company is actually getting benefits, definitely one of the first actions in a to improvement project is to be able to determine the current status of the process. Only by measuring it is possible to know the state of a process in an objective ay, and only through this it is possible to plan strategies and solutions, about improvements to make, depending on the objectives of the organization. This paper proposes a light model to assess software development process, which seeks to help the Colombian software development companies to determine whether the process of implementing improvements, being effective in achieving the objectives and goals set to implement this, through the use of measures to evaluate the process of improving their development processes, allowing characterize the current practices of the company, identifying weaknesses, strengths and abilities of the processes that are carried out within this and thus control or prevent the causes of low quality, or deviations in costs or planning.MSC: 68Uxx, 68NxxLas empresas de desarrollo de software en Colombia enfrentan una serie de problemas tales como la construcción de software de forma artesanal, empírica y desorganizada. Por esto, es necesario que implementen proyectos para mejorar sus procesos de desarrollo, ya que asegurar la calidad de los productos,a través de la mejora de sus procesos de software, es un paso que deben dar para estar en condiciones de competir en el mercado nacional e internacional. Implementar modelos de mejora de procesos no es suficiente para decir siuna empresa realmente está obteniendo beneficios, definitivamente una de las primeras acciones en un proyecto de mejora es el poder determinar el estadoactual del proceso. Sólo midiendo es posible conocer el estado de un proceso de manera objetiva, y sólo gracias a esto se pueden planificar estrategias y soluciones acerca delas mejoras a realizar y según los objetivos de la organización. Este artículo propone un modelo liviano de medidas para evaluar un proyecto de mejora deprocesos de software, con el cual se busca ayudar a las empresas de desarrollode software colombianas a determinar si el proceso de mejora que implementan está siendo eficaz con relación a los objetivos y metas establecidas al inicio del proyecto. Esto se lleva a cabo a través del uso de medidas que permiten evaluar el proceso de mejora de sus procesos, facilitando la caracterizaciónde las prácticas actuales de la empresa y la identificación de las debilidades, fortalezas y habilidades de los procesos que son llevados a cabo dentro de ésta, permitiendo controlar y evitar las causas de baja calidad y desviaciones encostos o en planificación.MSC: 68Uxx, 68Nx