Artículos de revista DEIO - EIOS Aldizkari artikuluak

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    PublicationOpen Access
    Accidente laboral. ACSOM una nueva orientación para gestión automática del riesgo
    (Gobierno de Navarra, 2009) García Felipe, Ana Isabel; Conte Soriano, Juan Carlos; Rubio Aranda, Encarnación; Pérez Prados, Antonio; Estadística e Investigación Operativa; Estatistika eta Ikerketa Operatiboa
    Fundamento. Analizar la accidentalidad laboral en todo tipo de empresas, a través de los riesgos que la provocan, teniendo en cuenta que el objetivo final es establecer una clasificación de riesgos prioritarios. Esta información permite abordar las acciones preventivas oportunas sobre los riesgos más vulnerables. Material y Métodos. Se aplica un conjunto de técnicas estadístico-matemáticas, basadas fundamentalmente en contrastes estadísticos, a los accidentes laborales acaecidos durante tres años, en un organismo de investigación y desarrollo español (I+D) con 8.780 trabajadores. Se utiliza como patrón de referencia en este estudio, para un análisis comparativo, el conjunto de accidentes en España durante un periodo de 11 años. Resultados. Tras la aplicación de la nueva metodología, los dos primeros riesgos que requieren acciones preventivas prioritarias son interacción con substancias agresivas y accidentes con maquinaria móvil. Si únicamente se hubieran considerado los dos riesgos con frecuencias más elevadas, sin tener en cuenta la vulnerabilidad de cada uno de ellos, los riesgos prioritarios hubieran sido sobreesfuerzos y caídas al mismo nivel. Conclusiones. El análisis proporciona una relación de los riesgos más vulnerables (puntos débiles), sobre los cuales actuar y de esta forma ser más efectivos a la hora de reducir la accidentalidad.
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    PublicationOpen Access
    Adherence to the Mediterranean diet reduces mortality in the Spanish cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC-Spain)
    (Cambridge University Press, 2011) Buckland, Genevieve; Agudo, Antonio; Travier, Noemie; Huerta, José María; Cirera, Lluís; Tormo, María José; Navarro, Carmen; Chirlaque, María Dolores; Moreno Iribas, Conchi; Ardanaz, Eva; Barricarte Gurrea, Aurelio; Etxeberria Andueza, Jaione; Marín, Pilar; Quirós, J. Ramón; Redondo, María Luisa; Larrañaga, Nerea; Amiano, Pilar; Dorronsoro, Miren; Arriola, Larraitz; Basterretxea, Mikel; Sánchez, María José; Molina, Esther; González, Carlos A.; Estadística e Investigación Operativa; Estatistika eta Ikerketa Operatiboa; Gobierno de Navarra / Nafarroako Gobernua
    Epidemiological studies show that adherence to a Mediterranean diet (MD) increases longevity; however, few studies are restricted to Mediterranean populations or explore the effect of a MD pattern that directly incorporates olive oil. Therefore the relationship between adherence to the MD and mortality was studied within the the Spanish cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC-Spain). The EPIC-Spain analysis included 40 622 participants (37·7% males) aged 29–69 years who were recruited from five Spanish regions in 1992–1996. During a mean follow-up of 13·4 years, 1855 deaths were documented: 913 from cancer, 399 from CVD, 425 from other causes and 118 from unknown causes of death. Risk of all-cause and cause-specific mortality was assessed according to the level of adherence to a relative MD (rMED) score, measured using an 18-unit scale incorporating nine selected dietary components. A high compared with a low rMED score was associated with a significant reduction in mortality from all causes (hazard ratio (HR) 0·79; 95% CI 0·69, 0·91), from CVD (HR 0·66; 95% CI 0·49, 0·89), but not from overall cancer (HR 0·92; 95% CI 0·75, 1·12). A 2-unit increase in rMED score was associated with a 6% (P,0·001) decreased risk of all-cause mortality. A high olive oil intake and moderate alcohol consumption contributed most to this association. In this Spanish cohort, following an olive oil-rich MD was related to a significant reduction in all-cause mortality, and reduced the risk of mortality from CVD. These results support the important role that the MD pattern has on reducing mortality in Mediterranean countries.
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    PublicationOpen Access
    Age- and sex-specific spatio-temporal patterns of colorectal cancer mortality in Spain (1975-2008)
    (BioMed Central, 2014) Etxeberria Andueza, Jaione; Ugarte Martínez, María Dolores; Goicoa Mangado, Tomás; Militino, Ana F.; Estadística e Investigación Operativa; Estatistika eta Ikerketa Operatiboa
    In this paper, space-time patterns of colorectal cancer (CRC) mortality risks are studied by sex and age group (50-69, ≥70) in Spanish provinces during the period 1975-2008. Space-time conditional autoregressive models are used to perform the statistical analyses. A pronounced increase in mortality risk has been observed in males for both age-groups. For males between 50 and 69 years of age, trends seem to stabilize from 2001 onward. In females, trends reflect a more stable pattern during the period in both age groups. However, for the 50-69 years group, risks take an upward trend in the period 2006-2008 after the slight decline observed in the second half of the period. This study offers interesting information regarding CRC mortality distribution among different Spanish provinces that could be used to improve prevention policies and resource allocation in different regions.
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    PublicationOpen Access
    Brain and central nervous system cancer incidence in Navarre (Spain), 1973-2008 and projections for 2014
    (Ivyspring, 2015) Etxeberria Andueza, Jaione; San Roman, E.; Burgui, R.; Guevara Eslava, Marcela; Moreno Iribas, Conchi; Urbina, M. J.; Ardanaz, Eva; Estadística e Investigación Operativa; Estatistika eta Ikerketa Operatiboa
    Different studies have pointed out Navarre as one of the regions of Spain with the highest incidence rates of brain and other central nervous system (CNS) cancer. Trend analysis for cancer incidence rates for long periods of time, might help determining risk factors as well as, assessing prevention actions involved in this disease. The objective of this study was to describe the incidence of brain and CNS cancer using data from the population-based cancer registry of Navarre, (Spain) during the period 1973-2008 and provide forecast figures up to-2014. Crude and age-standardized (world population) incidence rates of brain cancer per 100,000 person-years were calculated by the direct method separately by gender, area (Pamplona and others), and age-groups. Penalized splines for smoothing rates in the temporal dimensions were applied in order to estimate and forecast cancer incidence rates. Age-adjusted incidence rates showed an increase over the study and forecast periods in both sexes more marked in women than in men. Higher incidence rates were observed in men compared with women but the differences became smaller with time. The increase was due to the rise of rates in the oldest age groups since the rates for younger age groups remained stable or decreased over time. As the entire aetiology of brain and other CNS cancer is not still clear, keep promoting healthful lifestyles for cancer primary prevention among the whole population is necessary.
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    PublicationOpen Access
    Cálculo de la distribución del tiempo de vida de componentes mediante autopsia en sistemas binarios aditivos, serie-paralelo y paralelo-serie
    (Universitat Politècnica de Catalunya, 1997) Mallor Giménez, Fermín; Azcárate Camio, Cristina; Pérez Prados, Antonio; Estadística e Investigación Operativa; Estatistika eta Ikerketa Operatiboa
    En este artículo se estudia el problema de determinar la función de distribución del tiempo de vida de las componentes de un sistema binario, a partir del conocimiento de las leyes que rigen el funcionamiento del sistema y del conjunto de componentes que causa su fallo (obtenida mediante autopsia del sistema en el momento de su deterioro). Se presentan los resultados de Meilijson (1981) y Nowik (1990) que proponen un sistema de ecuaciones impíıcito para obtener estas distribuciones. Sin embargo, se observa que este sistema es de muy difícil resolución práctica, por lo que nosotros consideramos un método cuya utilización es más restringida pero más sencilla, y estudiamos su aplicación a sistemas binarios aditivos, serie-paralelo y paralelo-serie.
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    PublicationOpen Access
    Characterization of genetic resources of onion (Allium cepa L.) from the Spanish secondary centre of diversity
    (Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), 2011) Mallor Giménez, Cristina; Carravedo Fantova, Miguel; Estopañán Muñoz, Gloria; Mallor Giménez, Fermín; Estadística e Investigación Operativa; Estatistika eta Ikerketa Operatiboa
    La cebolla es el segundo cultivo hortícola a nivel mundial. Sin embargo, el conocimiento sobre los recursos y la diversidad genética de esta especie es limitado. Por ello, el objetivo del presente trabajo consistió en el estudio morfológico y físico-químico de una colección de 86 cultivares de cebolla procedentes de España (que forma parte del centro secundario de diversificación). Los caracteres evaluados en el bulbo incluyeron: peso, forma, firmeza, contenido en sólidos solubles (SSC), pungencia y contenido en azúcares (glucosa, fructosa y sacarosa). Los resultados evidenciaron una gran variabilidad en todos los caracteres evaluados. Las correlaciones fueron significativas entre la pungencia y SSC (r = 0,34), firmeza (r = 0,32) y contenido en sacarosa (r = 0,34); entre contenido en fructosa y glucosa (r = 0,79); entre contenido en sacarosa y SSC (r = 0,57); entre SSC y peso (r = –0,35); entre contenido en fructosa y sacarosa (r = –0,22) y entre el peso y contenido en sacarosa (r = –0,43). El análisis discriminante dio lugar a la formación de cuatro grupos con un ajuste del 95,3%. El grupo 1 está formado por bulbos grandes, firmes y picantes, el grupo 2 por cebollas grandes, suaves y dulces, el grupo 3 por cebollas pequeñas, picantes y con un alto SSC y el grupo 4 por bulbos de forma alargada. La variabilidad encontrada para caracteres de interés agronómico indica que este material podría ser utilizado en futuros programas de mejora genética de esta especie. Además, la agrupación de los cultivares contribuiría a localizar mejor el material vegetal de interés y las correlaciones halladas entre los caracteres evaluados a establecer una adecuada estrategia de selección.
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    PublicationOpen Access
    Checking unimodality using isotonic regression: an application to breast cancer mortality rates
    (Springer, 2016) Rueda, C.; Ugarte Martínez, María Dolores; Militino, Ana F.; Estatistika eta Ikerketa Operatiboa; Institute for Advanced Materials and Mathematics - INAMAT2; Estadística e Investigación Operativa
    In some diseases it is well-known that a unimodal mortality pattern exists. A clear example in developed countries is breast cancer, where mortality increased sharply until the nineties and then decreased. This clear unimodal pattern is not necessarily applicable to all regions within a country. In this paper, we develop statistical tools to check if the unimodality pattern persists within regions using order restricted inference. Break points as well as confidence intervals are also provided. In addition, a new test for checking monotonicity against unimodality is derived allowing to discriminate between a simple increasing pattern and an up-then-down response pattern. A comparison with the widely used joinpoint regression technique under unimodality is provided. We show that the joinpoint technique could fail when the underlying function is not piecewise linear. Results will be illustrated using age-specific breast cancer mortality data from Spain in the period 1975-2005.
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    PublicationOpen Access
    Classical molecular tests using urine samples as a potential screening tool for human papillomavirus detection in human immunodeficiency virus-infected women
    (American Society for Microbiology, 2013) Muñoz Bobo, Marina; Camargo, Milena; Soto de León, Sara; Sánchez, Ricardo; Pineda Peña, Andrea; Pérez Prados, Antonio; Patarroyo, Manuel Elkin; Patarroyo, Manuel Alfonso; Estadística e Investigación Operativa; Estatistika eta Ikerketa Operatiboa
    Human papillomavirus (HPV) is the main risk factor associated with the development of cervical cancer (CC); however, there are other factors, such as immunosuppression caused by the human immunodeficiency virus (HIV), that favor progression of the illness. This study was thus aimed at evaluating the functionality of classical PCR-based molecular tests for the generic identification of HPV DNA (GP5 /GP6 , MY09/MY11, and pU1M/2R primers, individually or in combination) using cervical and urine samples from 194 HIV-positive women. Infected samples were tested with type-specific primers for six high-risk types (HPV-16, -18, -31, -33, -45, and -58) and two low-risk types (HPV-6 and -11). HPV infection prevalence rates were 70.1% for the cervical samples and 63.9% for the urine samples. HPV-16 was the most prevalent viral type in the cervical and urine samples, with higher rates of multiple infections than single infections detected in such samples. HPV DNA detection by PCR (mainly with the pU1M/2R primer set) in urine samples was positively associated with abnormal cytological findings (atypical squamous cells of undetermined significance/squamous intraepithelial lesions [ASCUS/SIL]). It was determined that the operative characteristics for detection of cytological abnormalities were similar for cervical and urine samples. This suggested using PCR for the detection of HPV DNA in urine samples as a potential screening strategy for CC prevention in future prevention and control programs along with currently implemented strategies for reducing the impact of the disease, i.e., urine samples are economical, are easy to collect, have wide acceptability among women, and have operative characteristics similar to those of cervical samples.
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    PublicationOpen Access
    A comparison of two modes of data collection: using multidimensional analysis
    (CSIC, 2012) Abascal Fernández, Elena; Díaz de Rada Igúzquiza, Vidal; García Lautre, Ignacio; Landaluce, M. Isabel; Estadística e Investigación Operativa; Estatistika eta Ikerketa Operatiboa; Sociología; Soziologia
    La investigación sobre comparación entre encuestas presenciales y telefónicas se ha reducido en los últimos años, concluyendo que los resultados son similares, pero los recientes desarrollos tecnológicos y cambios sociales han llevado a reabrir el debate. Además de los problemas relacionados con la falta de este equipamiento (o la dificultad para acceder a los que lo poseen como es el caso de los teléfonos móviles), es importante tener en cuenta también que la respuesta de una encuesta telefónica supone una situación social totalmente distinta a la respuesta de una encuesta en presencia del entrevistador. Ambas situaciones generan diferencias importantes entre las encuestas respondidas en presencia del entrevistador (cara a cara) y a través del teléfono. Se trata de un fenómeno que ha sido analizado por numerosas investigaciones, si bien la gran mayoría han llevado a cabo una comparación “variable a variable”, con las limitaciones propias del análisis uni y bivariante. En el presente trabajo adoptaremos una perspectiva diferente, considerando conjuntamente todas las variables del cuestionario. Utilizaremos, para ello, el Análisis de Correspondencias Múltiples sobre una investigación del CIS realizada en el año 2005 sobre las elecciones autonómicas de Galicia (estudio número 2.608).
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    PublicationOpen Access
    Criterio de selección de un árbol óptimo según coeficientes de asociación derivados de χ²
    (Universitat Politècnica de Catalunya, 1996) Cano Sevilla, Francisco J.; Munduate del Río, Arantza; Pérez Prados, Antonio; Estadística e Investigación Operativa; Estatistika eta Ikerketa Operatiboa
    Se analiza en primer lugar la variación que se produce en el valor del coeficiente de contingencia al realizarse un proceso de poda en un árbol de decisión T. Conocido este efecto, se define una cantidad criterio que combina linealmente el coeficiente de contingencia con el índice de simplicidad. A partir de esta cantidad criterio, se propone un método de obtención de un árbol óptimo para cada uno de los distintos valores del parámetro α de la combinación lineal. Para seleccionar el árbol óptimo entre todos ellos se utiliza el coeficiente de Tschuprow, dependiente de las dos medidas consideradas para la calidad del árbol.
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    PublicationOpen Access
    Depletion of the heaviest stable N isotope is associated with NH4+/NH3 toxicity in NH4+-fed plants
    (BioMed Central, 2011) Ariz Arnedo, Idoia; Cruz, Cristina; Morán Juez, José Fernando; González Moro, María Begoña; García Olaverri, Carmen; González Murua, Carmen; Martins Loucao, María A.; Aparicio Tejo, Pedro María; Estatistika eta Ikerketa Operatiboa; Estadística e Investigación Operativa; IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua
    Background: In plants, nitrate (NO3-) nutrition gives rise to a natural N isotopic signature (δ15N), which correlates with the δ15N of the N source. However, little is known about the relationship between the δ15N of the N source and the 14N/15N fractionation in plants under ammonium (NH4+) nutrition. When NH4 + is the major N source, the two forms, NH4 + and NH3, are present in the nutrient solution. There is a 1.025 thermodynamic isotope effect between NH3 (g) and NH4 + (aq) which drives to a different δ15N. Nine plant species with different NH4 +-sensitivities were cultured hydroponically with NO3 - or NH4 + as the sole N sources, and plant growth and δ15N were determined. Short-term NH4 +/NH3 uptake experiments at pH 6.0 and 9.0 (which favours NH3 form) were carried out in order to support and substantiate our hypothesis. N source fractionation throughout the whole plant was interpreted on the basis of the relative transport of NH4 + and NH3. Results: Several NO3 --fed plants were consistently enriched in 15N, whereas plants under NH4 + nutrition were depleted of 15N. It was shown that more sensitive plants to NH4 + toxicity were the most depleted in 15N. In parallel, N-deficient pea and spinach plants fed with 15NH4 + showed an increased level of NH3 uptake at alkaline pH that was related to the 15N depletion of the plant. Tolerant to NH4 + pea plants or sensitive spinach plants showed similar trend on 15N depletion while slight differences in the time kinetics were observed during the initial stages. The use of RbNO3 as control discarded that the differences observed arise from pH detrimental effects. Conclusions: This article proposes that the negative values of δ15N in NH4 +-fed plants are originated from NH3 uptake by plants. Moreover, this depletion of the heavier N isotope is proportional to the NH4 +/NH3 toxicity in plants species. Therefore, we hypothesise that the low affinity transport system for NH4 + may have two components: one that transports N in the molecular form and is associated with fractionation and another that transports N in the ionic form and is not associated with fractionation.
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    PublicationOpen Access
    Desigualdades socioeconómicas en la mortalidad en Pamplona y Logroño en el periodo 1996-2007
    (Gobierno de Navarra. Departamento de Salud, 2013) Izco Goñi, N.; Etxeberria Andueza, Jaione; Delfrade Osinaga, J.; Floristan, Y.; Moreno Iribas, Conchi; Estadística e Investigación Operativa; Estatistika eta Ikerketa Operatiboa
    Fundamento. Describir las desigualdades en mortalidad en Logroño y Pamplona, ciudades del norte de España, utilizando un indicador de privación socioeconómica por secciones censales. Métodos. Para geocodificar la residencia de los fallecidos en base a las unidades censales se utilizó la dirección postal del Boletín Estadístico de Defunción y en su defecto la del Padrón Municipal o Tarjeta Sanitaria. Las variables socioeconómicas que componen el índice de privación se obtuvieron del Censo de Población y Vivienda de 2001. Se agruparon las secciones censales por quintiles de menor a mayor privación socioeconómica y se calcularon tasas ajustadas para la mortalidad total y para una lista de causas por sexo, grupo de edad (0-64, ≥ 65) y quintil del índice de privación socioeconómico. Resultados. La comparación de la mortalidad de las zonas con menor privación socioeconómica respecto a zonas geográficas con mayor privación mostró en ambas ciudades una mayor mortalidad principalmente entre los hombres menores de 65 años. En este subgrupo se observó un gradiente positivo entre la mortalidad y el índice de privación. Las zonas situadas en el quintil de mayor privación alcanzaron un riesgo relativo (RR) de 1,61 (IC 95%, 1,33-1,92) en Pamplona y de 1,77 (IC 95%, 1,55-2,01) en Logroño. Las mujeres menores de 65 años mostraron un RR de 1,44 (IC 95%, 1,18-1,74) y de 1,48 (IC 95%, 1,10-1,95) en las zonas situadas en el quintil de mayor privación de Pamplona y Logroño, respectivamente. Conclusiones. El estudio evidenció desigualdades en mortalidad asociadas a la privación socioeconómica en las ciudades de Logroño y Pamplona. También mostró la utilidad de los indicadores socioeconómicos y de mortalidad a nivel de área pequeña para identificar desigualdades en salud
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    PublicationOpen Access
    The DNA load of six high-risk human papillomavirus types and its association with cervical lesions
    (BioMed Central, 2015) Río Ospina, Luisa del; Soto de León, Sara; Camargo, Milena; Moreno Pérez, Darwin Andrés; Sánchez, Ricardo; Pérez Prados, Antonio; Patarroyo, Manuel Elkin; Patarroyo, Manuel Alfonso; Estadística e Investigación Operativa; Estatistika eta Ikerketa Operatiboa
    Background: Analysing human papillomavirus (HPV) viral load is important in determining the risk of developing cervical cancer (CC); most knowledge to date regarding HPV viral load and cervical lesions has been related to HPV-16. This study evaluated the association between the viral load of the six most prevalent high-risk viral types in Colombia and cervical intraepithelial neoplasia (CIN) frequency. Methods: 114 women without CIN and 59 women having CIN confirmed by colposcopy, all of them positive by conventional PCR for HPV infection in the initial screening, were included in the study. Samples were tested for six high-risk HPV types to determine viral copy number by real-time PCR. Crude and adjusted odds ratios (ORa) were estimated for evaluating the association between each viral type's DNA load and the risk of cervical lesions occurring. Results: The highest viral loads were identified for HPV-33 in CIN patients and for HPV-31 in patients without lesions (9.33 HPV copies, 2.95 interquartile range (IQR); 9.41 HPV copies, 2.58 IQR). Lesions were more frequent in HPV-16 patients having a low viral load (3.53 ORa, 1.16-10.74 95%CI) compared to those having high HPV-16 load (2.62 ORa, 1.08-6.35 95%CI). High viral load in HPV-31 patients was associated with lower CIN frequency (0.34 ORa, 0.15-0.78 95%CI). Conclusions: An association between HPV DNA load and CIN frequency was seen to be type-specific and may have depended on the duration of infection. This analysis has provided information for understanding the effect of HPV DNA load on cervical lesion development.
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    PublicationOpen Access
    The effect of changing temperature and agar concentration at proliferation stage in the final success of Aleppo pine somatic embryogenesis
    (Instituto Nacional de Investigacion y Tecnologia Agraria y Alimentaria (INIA), 2017) Pereira, Catia; Montalbán, Itziar A.; Goicoa Mangado, Tomás; Ugarte Martínez, María Dolores; Correia, Sandra; Canhoto, Jorge M.; Moncaleán, Paloma; Estadística e Investigación Operativa; Estatistika eta Ikerketa Operatiboa
    Aim of the study: The effect of physical and chemical conditions at proliferation stage was evaluated in order to elucidate if this stage is the determinant phase to induce a marked effect in Pinus halepensis somatic embryogenesis. Area of study: The study was conducted in research laboratories of Neiker (Arkaute, Spain). Material and methods: Pinus halepensis embryonal masses from ten embryogenic cell lines subjected to nine treatments (tissues cultured at three temperatures on media supplemented with three agar concentrations) at proliferation stage. Main results: Significant differences were observed among different proliferation conditions months later at the end of maturation, germination and acclimatization stages. Research highlights: Aleppo pine embryonal masses are cultured under standard conditions on a culture medium supplemented with 4.5 g/L Gelrite® at 23ºC. However, better results in terms of plantlet production can be obtained proliferating the embryonal masses at 18ºC in a culture media with significantly lower water availability.
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    Electric vehicles in logistics and transportation: a survey on emerging environmental, strategic, and operational challenges
    (MDPI, 2016) Juan Pérez, Ángel Alejandro; Méndez, Carlos Alberto; Faulín Fajardo, Javier; Armas, Jesica de; Grasman, Scott Erwin; Estadística e Investigación Operativa; Estatistika eta Ikerketa Operatiboa
    Current logistics and transportation (L&T) systems include heterogeneous fleets consisting of common internal combustion engine vehicles as well as other types of vehicles using “green” technologies, e.g., plug-in hybrid electric vehicles and electric vehicles (EVs). However, the incorporation of EVs in L&T activities also raise some additional challenges from the strategic, planning, and operational perspectives. For instance, smart cities are required to provide recharge stations for electric-based vehicles, meaning that investment decisions need to be made about the number, location, and capacity of these stations. Similarly, the limited driving-range capabilities of EVs, which are restricted by the amount of electricity stored in their batteries, impose non-trivial additional constraints when designing efficient distribution routes. Accordingly, this paper identifies and reviews several open research challenges related to the introduction of EVs in L&T activities, including: (a) environmental-related issues; and (b) strategic, planning and operational issues associated with “standard” EVs and with hydrogen-based EVs. The paper also analyzes how the introduction of EVs in L&T systems generates new variants of the well-known Vehicle Routing Problem, one of the most studied optimization problems in the L&T field, and proposes the use of metaheuristics and simheuristics as the most efficient way to deal with these complex optimization problems.
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    Estimating unemployment in very small areas
    (Institut d'Estadística de Catalunya-IDESCAT, 2009) Ugarte Martínez, María Dolores; Goicoa Mangado, Tomás; Militino, Ana F.; Sagaseta López, M.; Estadística e Investigación Operativa; Estatistika eta Ikerketa Operatiboa
    In the last few years, European countries have shown a deep interest in applying small area techniques to produce reliable estimates at county level. However, the specificity of every European country and the heterogeneity of the available auxiliary information, make the use of a common methodology a very difficult task. In this study, the performance of several design-based, model-assisted, and model-based estimators using different auxiliary information for estimating unemployment at small area level is analyzed. The results are illustrated with data from Navarre, an autonomous region located at the north of Spain and divided into seven small areas. After discussing pros and cons of the different alternatives, a composite estimator is chosen, because of its good trade-off between bias and variance. Several methods for estimating the prediction error of the proposed estimator are also provided.
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    Evaluation of grape stems and grape stem extracts for sulfur dioxide replacement during grape wine production
    (Elsevier, 2023) Pires Nogueira, Danielle; Jiménez Moreno, Nerea; Esparza Catalán, Irene; Moler Cuiral, José Antonio; Ferreira-Santos, Pedro; Sagüés Sarasa, Ana; Teixeira, José António; Ancín Azpilicueta, Carmen; Ciencias; Zientziak; Estadística e Investigación Operativa; Estatistika eta Ikerketa Operatiboa; Institute for Advanced Materials and Mathematics - INAMAT2
    Sulfur dioxide (SO2), the main preservative in wine, may affect the sensory properties of the wines, as well as cause allergic reactions and headaches in sensitive people. The aim of this work was to evaluate the replacement of SO2 in Tempranillo wines with Mazuelo grape stem products. Five Tempranillo red wines were elaborated: positive control (60 mg/L SO2); negative control with no preservatives; Mazuelo extract (200 mg/L); Mazuelo extract combined with SO2 (100 mg/L + 20 mg/L); and Mazuelo stem (400 mg/L). The oenological parameters, antioxidant capacity, total phenolic (TP), total flavonoids (TF) and total anthocyanins (TA) contents were determined. Additionally, individual phenols were analyzed by HPLC-DAD-FLD. The spectrophotometric analyses showed that the wines had similar antioxidant capacities and concentrations of TP and TF. However, TA was more affected by the lack of SO2 as anthocyanins presented higher concentrations in positive control samples. The concentrations of individual phenols followed a similar path in all samples. Wines containing sulfites were more similar than the other treatments. However, these similarities were not reflected on the sensory analysis performed, as triangle test did not show differences between the wine with extract addition and the positive control wine. Therefore, Mazuelo stem extract could be a possible strategy for SO2 replacement. Nevertheless, further studies are necessary to confirm the potential of grape stem extracts as wine preservative.
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    Horizontal collaboration in freight transport: concepts, benefits and environmental challenges
    (Institut d'Estadística de Catalunya, 2017) Serrano Hernández, Adrián; Juan Pérez, Ángel Alejandro; Faulín Fajardo, Javier; Pérez Bernabeu, Elena; Estatistika eta Ikerketa Operatiboa; Institute of Smart Cities - ISC; Estadística e Investigación Operativa
    Since its appearance in the 1990s, horizontal collaboration (HC) practices have revealed them-selves as catalyzers for optimizing the distribution of goods in freight transport logistics. After introducing the main concepts related to HC, this paper offers a literature review on the topic and provides a classification of best practices in HC. Then, the paper analyses the main benefits and optimization challenges associated with the use of HC at the strategic, tactical, and operational levels. Emerging trends such as the concept of ‘green’ or environmentally-friendly HC in freighttransport logistics are also introduced. Finally, the paper discusses the need of using hybrid optimization methods, such as simheuristics and learnheuristics, in solving some of the previously identified challenges in real-life scenarios dominated by uncertainty and dynamic conditions.
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    PublicationOpen Access
    Human papillomavirus detection from human immunodeficiency virus-infected Colombian women’s paired urine and cervical samples
    (Public Library of Science, 2013) Muñoz Bobo, Marina; Camargo, Milena; Soto de León, Sara; Sánchez, Ricardo; Parra, Diana; Pineda Peña, Andrea; Sussmann, Otto; Pérez Prados, Antonio; Patarroyo, Manuel Elkin; Patarroyo, Manuel Alfonso; Estadística e Investigación Operativa; Estatistika eta Ikerketa Operatiboa
    Infection, coinfection and type-specific human papillomavirus (HPV) distribution was evaluated in human immunodeficiency virus (HIV)-positive women from paired cervical and urine samples. Paired cervical and urine samples (n = 204) were taken from HIV-positive women for identifying HPV-DNA presence by using polymerase chain reaction (PCR) with three generic primer sets (GP5+/6+, MY09/11 and pU1M/2R). HPV-positive samples were typed for six high-risk HPV (HR-HPV) (HPV-16, -18, -31, -33, -45 and -58) and two low-risk (LR-HPV) (HPV-6/11) types. Agreement between paired sample results and diagnostic performance was evaluated. HPV infection prevalence was 70.6% in cervical and 63.2% in urine samples. HPV-16 was the most prevalent HPV type in both types of sample (66.7% in cervical samples and 62.0% in urine) followed by HPV-31(47.2%) in cervical samples and HPV-58 (35.7%) in urine samples. There was 55.4% coinfection (infection by more than one type of HPV) in cervical samples and 40.2% in urine samples. Abnormal Papanicolau smears were observed in 25.3% of the women, presenting significant association with HPV-DNA being identified in urine samples. There was poor agreement of cervical and urine sample results in generic and type-specific detection of HPV. Urine samples provided the best diagnosis when taking cytological findings as reference. In conclusion including urine samples could be a good strategy for ensuring adherence to screening programs aimed at reducing the impact of cervical cancer, since this sample is easy to obtain and showed good diagnostic performance.
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    PublicationOpen Access
    Human papillomavirus detection in women with and without human immunodeficiency virus infection in Colombia
    (BioMed Central, 2014) Camargo, Milena; Soto de León, Sara; Muñoz Bobo, Marina; Sánchez, Ricardo; Peña-Herrera, Diego; Pineda Peña, Andrea; Sussmann, Otto; Paez, Carol; Pérez Prados, Antonio; Patarroyo, Manuel Elkin; Patarroyo, Manuel Alfonso; Estadística e Investigación Operativa; Estatistika eta Ikerketa Operatiboa
    Background: HIV infection leads to a decreasing immune response, thereby facilitating the appearance of other infections, one of the most important ones being HPV. However, studies are needed for determining associations between immunodeficiency caused by HIV and/or the presence of HPV during the course of cervical lesions and their degree of malignancy. This study describes the cytological findings revealed by the Papanicolaou test, laboratory characteristics and HPV molecular profile in women with and without HIV infection. Methods: A total of 216 HIV-positive and 1,159 HIV-negative women were invited to participate in the study; PCR was used for the molecular detection of HPV in cervical samples. Statistical analysis (such as percentages, Chi-square test and Fisher's exact test when applicable) determined human papillomavirus (HPV) infection frequency (single and multiple) and the distribution of six types of high-risk-HPV in women with and without HIV infection. Likewise, a logistic regression model was run to evaluate the relationship between HIV-HPV infection and different risk factors. Results: An association was found between the frequency of HPV infection and infection involving 2 or more HPV types (also known as multiple HPV infection) in HIV-positive women (69.0% and 54.2%, respectively); such frequency was greater than that found in HIV-negative women (44.3% and 22.7%, respectively). Statistically significant differences were observed between both groups (p = 0.001) regarding HPV presence (both in infection and multiple HPV infection). HPV-16 was the most prevalent type in the population being studied (p = 0.001); other viral types had variable distribution in both groups (HIV-positive and HIV-negative). HPV detection was associated with <500 cell/mm(3) CD4-count (p = 0.004) and higher HIV-viral-load (p = 0.001). HPV-DNA detection, <200 cell/mm(3) CD4-count (p = 0.001), and higher HIV-viral-load (p = 0.001) were associated with abnormal cytological findings. Conclusions: The HIV-1 positive population in this study had high multiple HPV infection prevalence. The results for this population group also suggested a greater association between HPV-DNA presence and cytological findings. HPV detection, together with low CD4 count, could represent useful tools for identifying HIV-positive women at risk of developing cervical lesions.