Health insurance as a strategy for access: streamlined facts of the colombian health care reform

The Colombian reform to the health system (Law 100 of 1993) established, as strategy to facilitate the access, the universality of a health insurance that is acquired by means of the quotation in the contributive regime or by means of the gratuitous affiliation to the subsidized regime, in order to cover all the population with a unique plan of benefits that includes services in all levels of complexity. In this paper we intend to cover the main streamlined facts of the reform as far as coverage and access of the insurance, by means of logit models, the determinants of the enrollment and the access are considered, using data from the Living Standards Surveys of 1997 and 2003. It stands out that the coverage rose from 20% of the population in 1993 to 60% in 2003, although it seems very difficult to reach the universality; the structure and evolution of the coverage show that both regimes complement each other, while the contributive one has greater presence in the cities and among the population with formal employment, the subsidized one has greater weight among the rural population and in those with low levels of income; on the other hand, the insurance has advantages for the subsidized population, with a greater probability for use of the services, although the plan offers less benefits than the contributive one there are some barriers for the access.health insurance, access, enrollment affiliation, social security, Colombia

On the use of machine learning algorithms in the measurement of stellar magnetic fields

Regression methods based in Machine Learning Algorithms (MLA) have become an important tool for data analysis in many different disciplines. In this work, we use MLA in an astrophysical context; our goal is to measure the mean longitudinal magnetic field in stars (H_ eff) from polarized spectra of high resolution, through the inversion of the so-called multi-line profiles. Using synthetic data, we tested the performance of our technique considering different noise levels: In an ideal scenario of noise-free multi-line profiles, the inversion results are excellent; however, the accuracy of the inversions diminish considerably when noise is taken into account. In consequence, we propose a data pre-process in order to reduce the noise impact, which consists in a denoising profile process combined with an iterative inversion methodology. Applying this data pre-process, we have found a considerable improvement of the inversions results, allowing to estimate the errors associated to the measurements of stellar magnetic fields at different noise levels. We have successfully applied our data analysis technique to two different stars, attaining by first time the measurement of H_eff from multi-line profiles beyond the condition of line autosimilarity assumed by other techniques.Comment: Accepted for publication in A&

Identificación de un modelo de capacidades operativas en un centro de distribución de una empresa de productos de distribución eléctrica en Bogotá

El documento presenta la compilación de los diferentes modelos de capacidades logísticas operacionales con el fin de identificar el modelo de seguimiento operativo que se ajuste a una empresa de productos de distribución eléctrica con el fin de evaluar sus ineficiencias en términos de capacidades operacionales y minimizar sus pérdidas de ventas y/o clientes potenciales por fallas logísticas.Faced with changing investment scenarios and the development of economic policies in a country, businessmen need to adjust their requirements and adapt their strategies in terms of cost and competitiveness. Therefore, this document presents a compilation of existing operational logistic capacities models that allow a distribution electric components company to make the best decision to adjust its capabilities according to the sales forecast and /or historical data, in such a way that an integrated model of capacities could be adapted to the company’s constraints and particularities

Continuous light on tomato : from gene to yield

Light essentially sustains all life on planet earth surface. Plants transform light energy into chemical energy through photosynthesis. Hence, it can be anticipated that extending the daily photoperiod, using artificial light, results in increased plant productivity. Although this premise is true for many plant species, a limit exists. For instance, the seminal work of Arthur et al. (1930) showed that tomato plants develop leaf injuries if exposed to continuous light (CL). Many studies have investigated the physiological mechanism inducing such CL-induced injury. Although important and valuable discoveries were done over the decades, by the time the present project started, a detailed and proven physiological explanation of this disorder was still missing. Here, I present the results of a 5-year effort to better understand the physiological basis of the CL-induced injury in tomato and develop the tools (genetic and conceptual) to cultivate tomatoes under CL. After an exhaustive literature search, it was found that Daskaloff and Ognjanova (1965) reported that wild tomato species are tolerant to CL. Unfortunately, this important finding was ignored by numerous studies done after its publication. Here, we used the CL-tolerance found in wild tomatoes as a fundamental resource. Hence, the specific objectives of this thesis were to (i) better understand the physiological basis of the CL-induced injuries in tomato, (ii) identify the gene(s) responsible for CL-tolerance in wild tomato species, (iii) breed a CL-tolerant tomato line and (iv) use it to cultivate a greenhouse tomato crop under CL. Chapter 1 describes how innovation efforts encountered the unsolved scientific enigma of the injuries that tomato plants develop when exposed to CL. The term CL-induced injury is defined, and a detailed description of the symptoms observed in this disorder is shown. Additionally, an overview of the most important studies, influencing the hypotheses postulated and/or tested in this dissertation, is presented. Finally, a description and motivation of the main questions that this dissertation pursued to answer is presented alongside a short description of the strategy chosen to answer them. Chapter 2 reviews the literature, published over the last 80 years, on CL-induced injury using modern knowledge of plant physiology. By doing so, new hypotheses aiming to explain this disorder are postulated in addition to the ones collected from literature. Additionally, we highlight that CL is an essential tool for understanding the plant circadian clock, but using CL in research has its challenges. For instance, most of the circadian-clock-oriented experiments are performed under CL; consequently, interactions between the circadian clock and the light signalling pathway are overlooked. This chapter is published here. Chapter 3 explores the benefits and challenges of cultivating CL-tolerant tomato under CL. Considering that current commercial tomato varieties need six hours of darkness per day for optimal growth, photosynthesis does not take place during a quarter of the day. Hence, if tomatoes could be grown under CL, a substantial increase in production is anticipated. A simulation study is presented, which shows that if an ideal continuous-light-tolerant tomato genotype is used and no crop adaptations to CL are assumed, greenhouse tomato production could be 26% higher when supplementing light to 24 h day-1 in comparison with a photoperiod (including supplementary lighting) of only 18 h day-1. In addition, the expected changes in greenhouse energy budgets and alterations in crop physiological responses that might arise from cultivating tomatoes under continuous light are discussed. This chapter is published here. Chapter 4 maps the locus conferring CL-tolerance in wild tomatoes to chromosome seven, and shows that its introgression into modern tomato cultivars enhances yield by 20%, when grown under CL. In addition, genetic evidence, RNAseq data, silencing experiments and sequence analysis all point to the type III Light-Harvesting Chlorophyll a/b Binding protein 13 (CAB-13) gene as a major factor responsible for the tolerance. In Arabidopsis thaliana this protein is thought to have a regulatory role in balancing light harvesting by photosystems I and II. The likely mechanisms that link CAB-13 with CL-tolerance are discussed. This chapter is published here. Chapter 5 investigates from which part of the plant CL-tolerance originates and whether this trait acts systemically. By exposing grafted plants bearing both tolerant and sensitive shoots to CL, the trait was functionally located to the shoot rather than the roots. Additionally, an increase in continuous-light tolerance was observed in sensitive plants when a continuous-light-tolerant shoot was grafted on it. Our results show that in order to increase yield in greenhouse tomato production by using CL, the trait should be bred into scion rather than rootstock lines. Chapter 6 discusses the factors that differ between injurious and non-injurious light regimes. Each of these factors may potentially be responsible for triggering the injury in CL-grown tomato and was experimentally tested here. In short, these factors include (i) differences in the light spectral distribution between sunlight and artificial light, (ii) continuous signalling to the photoreceptors, (iii) constant supply of light for photosynthesis, (iv) constant photo-oxidative pressure, and (v) circadian asynchrony — a mismatch between the internal circadian clock frequency and the external light/dark cycles. The evidence presented here suggests that the continuous-light-induced injury does not result from the unnatural spectral distribution of artificial light or the continuity of the light per se. Instead, circadian asynchrony seems to be the factor inducing the injury. As the discovered diurnal fluctuations in photoinhibition sensitivity of tomato seedlings are not under circadian control, it seems that circadian asynchrony does not directly induce injury via photoinhibition as it has been proposed. Chapter 7 investigates a possible role for phytochromes (PHY) in CL-induced injury in tomato. Mutant and transgenic tomato plants lacking or over-expressing phytochromes were exposed to CL, with and without far-red light enrichment, to test the role of individual phytochromes on the induction and/or prevention of injury. PHYA over-expression confers complete tolerance to CL regardless the light spectrum. Under CL with low far-red content, PHYB1 and PHYB2 diminished and enhanced the injury, respectively, yet the effects were small. These results confirm that phytochrome signaling networks are involved in the injury induction under CL. The link between CAB-13 and PHYA is discussed. Chapter 8 investigates the role of carbohydrate accumulation in the induction of CL-induced injury in tomato by using untargeted metabolomics and transcriptomics data. These data reveal a clear effect of CL on sugar metabolism and photosynthesis. A strong negative correlation between sucrose and starch with the maximum quantum efficiency of photosystem II (Fv /Fm) was found across several abnormal light/dark cycles, supporting the hypothesis that carbohydrates play an important role in CL-induced injury. I suggest that CL-induced injury in tomato is caused by a photosynthetic down-regulation showing characteristics of both cytokinin-regulated senescence and light-modulated retrograde signaling. Molecular mechanisms linking carbohydrate accumulation with photosynthetic down-regulation are discussed. Chapter 9 provides a synthesis of the most important findings and proposes a generic model of CL-induced injury in tomato. I propose that CL-induced injury in tomato arises from retrograde signals that counteract signals derived from the cellular developmental program that promote chloroplast development, such that chloroplast development cannot be completed, resulting in the chlorotic phenotype. Finally, perspectives on what future directions to take to further elucidate the physiological basis of this trait and successfully implement it in greenhouses are presented.</p