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Papers by arturo ivan luna garcia

The probabilistic clustering techniques can be applied to generate fuzzy sets in situations where... more The probabilistic clustering techniques can be applied to generate fuzzy sets in situations where there is little or no information about data. Quite often, they generate a huge number of clusters. These clusters can be interpreted as fuzzy sets in a process of building a fuzzy system. A large number of fuzzy sets introduce noise to the fuzzy system, hence the need to reduce their number. Fuzzy Similarity Measures (FSMs) are widely used for comparison of fuzzy sets. Multiple FSMs have been proposed so far, but identifying a single FSM that is the most suitable for a given task is not always a straightforward process. On many occasions, FSMs are used to reduce a number of fuzzy sets. In this paper, we present the results of analyzing suitability of FSMs to reduce number of fuzzy sets and fuzzy if-then rules for an image segmentation problem. We use a PG-Means algorithm to generate fuzzy sets on both input and output variables. We propose and apply algorithms utilizing FSMs to reduce ...

Microphyllous and rosetophyllous desert scrub plant communities dominate large parts of the state... more Microphyllous and rosetophyllous desert scrub plant communities dominate large parts of the state of Coahuila, Mexico, yet differences in how livestock grazing impacts these two plant communities are not well documented. In order to address this knowledge gap, we assessed livestock impact on plant species composition and vegetation structure in microphyllous and rosetophyllous desert scrublands in this northwestern Mexican state. We collected plant density, frequency, and cover data from sites with and without livestock grazing pressure that were otherwise similar in plant composition. We quantified intersite differences using the importance value index (IVI) and the Bray-Curtis similarity index. The species with the highest IVI for microphyllous scrubland were lechuguilla (Agave lechuguilla), honey mesquite (Prosopis glandulosa), and creosote bush (Larrea tridentata); however, in sites with presence of domestic herbivores, desert willow (Chilopsis linearis) and spiny hackberry (Cel...

Diabetes technology & therapeutics, Jan 11, 2017

High levels of glycemic variability are still observed in most patients with diabetes with severe... more High levels of glycemic variability are still observed in most patients with diabetes with severe insulin deficiency. Glycemic variability may be an important risk factor for acute and chronic complications. Despite its clinical importance, there is no consensus on the optimum method for characterizing glycemic variability. We developed a simple new metric, the glycemic variability percentage (GVP), to assess glycemic variability by analyzing the length of the continuous glucose monitoring (CGM) temporal trace normalized to the duration under evaluation. The GVP is similar to other recently proposed glycemic variability metrics, the distance traveled, and the mean absolute glucose (MAG) change. We compared results from distance traveled, MAG, GVP, standard deviation (SD), and coefficient of variation (CV) applied to simulated CGM traces accentuating the difference between amplitude and frequency of oscillations. The GVP metric was also applied to data from clinical studies for the D...

Diabetes technology & therapeutics, Jun 1, 2017

The potential clinical benefits of continuous glucose monitoring (CGM) have been recognized for m... more The potential clinical benefits of continuous glucose monitoring (CGM) have been recognized for many years, but CGM is used by a small fraction of patients with diabetes. One obstacle to greater use of the technology is the lack of simplified tools for assessing glycemic control from CGM data without complicated visual displays of data. We developed a simple new metric, the personal glycemic state (PGS), to assess glycemic control solely from continuous glucose monitoring data. PGS is a composite index that assesses four domains of glycemic control: mean glucose, glycemic variability, time in range and frequency and severity of hypoglycemia. The metric was applied to data from six clinical studies for the G4 Platinum continuous glucose monitoring system (Dexcom, San Diego, CA). The PGS was also applied to data from a study of artificial pancreas comparing results from open loop and closed loop in adolescents and in adults. The new metric for glycemic control, PGS, was able to charac...

Alabe Revista de Investigación sobre Lectura y Escritura, 2015

Computer-Aided Design of User Interfaces VI, 2009

Space deserves a special attention when designing 3D user interfaces. However, many proposed meth... more Space deserves a special attention when designing 3D user interfaces. However, many proposed methods rely on simple sketches and/or maps. Besides, those methods usually leave aside the 2D interfaces that may be found in the 3D environment or that surround it. This chapter presents an attempt to formalize 2D and 3D spaces by the definition of a meta-model. This is one of three meta-models that have been defined in three-dimensional user interface development methodology, which is also described here along with some case studies, focusing the description on space. V. López-Jaquero et al. (eds.

Surgery, 2014

Papillary thyroid carcinoma (PTC) with BRAF mutation carries a poorer prognosis. Prophylactic cen... more Papillary thyroid carcinoma (PTC) with BRAF mutation carries a poorer prognosis. Prophylactic central neck dissection (CND) reduces locoregional recurrences, and we hypothesize that initial total thyroidectomy (TT) with CND in patients with BRAF-mutated PTC is cost effective. This cost-utility analysis is based on a hypothetical cohort of 40-year-old women with small PTC [2 cm, confined to the thyroid, node(-)]. We compared preoperative BRAF testing and TT+CND if BRAF-mutated or TT alone if BRAF-wild type, versus no testing with TT. This analysis took into account treatment costs and opportunity losses. Key variables were subjected to sensitivity analysis. Both approaches produced comparable outcomes, with costs of not testing being lower (-$801.51/patient). Preoperative BRAF testing carried an excess expense of $33.96 per quality-adjusted life-year per patient. Sensitivity analyses revealed that when BRAF positivity in the testing population decreases to 30%, or if the overall nonc...

2014 IEEE International Conference on Fuzzy Systems (FUZZ-IEEE), 2014

ABSTRACT

Surgery, 2013

Background. Routine prophylactic central neck dissection (pCND) after total thyroidectomy (TTX) f... more Background. Routine prophylactic central neck dissection (pCND) after total thyroidectomy (TTX) for low-risk papillary thyroid cancer (PTC) offers the potential to decrease disease recurrence but may increase operative complications. We hypothesized that routine pCND is not cost-effective in low-risk PTC. Methods. A Markov transition-state model was constructed to compare TTX with and without pCND. Outcome probabilities, utilities, and costs were estimated on the basis of literature review. The threshold for cost-effectiveness was 100,000perquality−adjustedlifeyear.Sensitivityanalysiswasusedtoexaminemodeluncertainty.Results.pCNDcost100,000 per quality-adjusted life year. Sensitivity analysis was used to examine model uncertainty. Results. pCND cost 100,000perquality−adjustedlifeyear.Sensitivityanalysiswasusedtoexaminemodeluncertainty.Results.pCNDcost10,315 and produced an effectiveness of 23.785 quality-adjusted life years. This strategy was more costly and less effective than TTX without pCND and was therefore dominated. pCND became cost-effective when the probability of recurrence increased from 6% to 10.3%, cost of reoperation for recurrence increased from 8,900to8,900 to 8,900to26,120, or added probabilities of recurrent laryngeal nerve injury and hypoparathyroidism due to pCND were less than 0.20% and 0.18% during 2-way sensitivity analysis. Monte Carlo simulation showed that pCND was not cost-effective in 97.3% of iterations. Conclusion. Routine pCND for low-risk PTC is not cost-effective unless the recurrence rate is greater than 10.3%. Application of pCND should be individualized based on risk of recurrence and added complications.

Journal of Surgical Research, 2013

genomic composite score obtained in the first 24 hours after trauma can identify trauma patients ... more genomic composite score obtained in the first 24 hours after trauma can identify trauma patients who are likely to develop a complicated clinical trajectories. A novel platform is described in which this genomic score can be obtained within 12 hours of blood collection, making it available for clinical decision making. Such a prognosticator, if validated prospectively, can be used in future clinical interventions to identify trauma patients who are not likely to have a complicated clinical outcome and would not benefit from interventional therapies. 33.9. A Pilot Study of Hyper-coagulability Among Trauma Patients Who Smoke and the Impact of Nicotine Replacement Therapy.

Geology, 2001

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HCI International, 2005

This paper describes the development of an e-commerce Web site based on a virtual world that repl... more This paper describes the development of an e-commerce Web site based on a virtual world that replicates a real store in order to offer a more familiar interface to the user, but overcoming the problems of reality offering a customized presentation of items to each ...

Manuscrits: revista d'història moderna, 2008

Se realiza un recorrido por las investigaciones habidas sobre el estamento eclesiástico español e... more Se realiza un recorrido por las investigaciones habidas sobre el estamento eclesiástico español en los siglos XVI y XVII a lo largo de los últimos treinta años, partiendo de la obra pionera de Domínguez Ortiz, y mostrando las distintas fases de la investigación, que no tendrá su gran impulso hasta los años noventa del siglo pasado. Se indican asimismo cuáles han sido los aspectos más tratados por la historiografía, como el impacto de la Reforma católica, los aspectos sociológicos, los medios de difusión doctrinal empleados por la Iglesia, y la respuesta de la feligresía ante esta campaña adoctrinadora. Palabras clave: Iglesia católica, siglos XVI-XVII, Reforma católica, historiografía, historia moderna de España. Resum. El clergat a l'Espanya dels segles XVI i XVII. Estat de la qüestió i darreres tendències Es fa un recorregut per les investigacions sobre l'estament eclesiàstic espanyol als segles XVI i XVII al llarg dels darrers trenta anys, partint de l'obra pionera de Domínguez Ortiz i mostrant les diferents fases de la investigació, que no assolirà el seu gran impuls fins als anys noranta del segle passat. S'assenyala, també, quins han estat els aspectes més tractats per la historiografia, com l'impacte de la Reforma catòlica, els aspectes sociològics, els mitjans de difusió doctrinal emprats per l'Església i la resposta de la feligresia davant d'aquesta campanya adoctrinadora.