Social inequalities, advanced maternal age, and birth weight. Evidence from a population-based study in Spain.

OBJECTIVE: To examine whether advanced maternal age (≥40 years) is linked to an increased likelihood of low or high birth weight among native and foreign-born mothers giving birth in Spain. METHOD: A cross-sectional study was conducted using a novel database provided by the Spanish National Statistics Office which links the 2011 Census with information on individual births (2011-2015) from the Vital Statistics (Natural Movement of the Population). First, multinomial logistic regression models were used to estimate the potential association between maternal age and the likelihood of having a baby with low or high birth weight. Second, average adjusted predictions of giving birth to children with low, high, and adequate weight for the origin and the maternal age at birth were also calculated. RESULTS: Findings indicate that women with advanced maternal age showed an increased probability of giving birth to low birth weight infants. Conversely, mothers aged below <30 years had an elevated risk for high birth weight infants. When considering maternal migratory status, the findings were mixed. On one hand, foreign-born mothers showed a higher likelihood of delivering infants with high birth weight; on the other, they displayed a lower risk of low birth weight among newborns in comparison to Spanish natives. CONCLUSIONS: The study addresses two key aspects. First, it highlights the increased risk of low birth weight in mothers delivering at an advanced age. Second, it emphasizes the importance of accounting for maternal migratory status when investigating the association between age at birth and birth weight outcomes among immigrant mothers.

Latina paradox in Spain? Arrival-cohort effects on the birthweight of newborns of Latina mothers.

This study analyses the arrival-cohort effects on the newborn birthweight of Latina women residing in Spain. First, it has been tested whether women of Latin American origin in Spain have an advantage in terms of birth outcomes, a pattern previously documented in the United States and referred to as the 'Latin American paradox'. Second, it has been examined whether this health advantage of Latina mothers varies by arrival cohort.A novel database provided by the Spanish National Statistics Office that links the 2011 Census with Natural Movement of the Population records from January 2011 to December 2015 has been used. Poisson regression models were applied to test for differences in the incidence rates of low birthweight (LBW) and high birthweight (HBW) among children of Latina and native mothers, controlling for various demographic, socio-economic, and birth characteristics.Two distinct arrival-cohort effects on perinatal health were observed. On one hand, first-generation Latina women were found to be at a lower risk of giving birth to LBW infants; however, they experienced a higher incidence of HBW during the study period. Second, Latina women of 1.5 generation, likely stressed by increased exposure to the receiving country, exhibited adverse birthweight results.

Social inequalities, advanced maternal age, and birth weight. Evidence from a population-based study in Spain / Desigualdades sociales, edad materna avanzada y peso al nacer. Evidencia de un estudio basado en la población en España

Objective To examine whether advanced maternal age (≥40 years) is linked to an increased likelihood of low or high birth weight among native and foreign-born mothers giving birth in Spain. Method A cross-sectional study was conducted using a novel database provided by the Spanish National Statistics Office which links the 2011 Census with information on individual births (2011-2015) from the Vital Statistics (Natural Movement of the Population). First, multinomial logistic regression models were used to estimate the potential association between maternal age and the likelihood of having a baby with low or high birth weight. Second, average adjusted predictions of giving birth to children with low, high, and adequate weight for the origin and the maternal age at birth were also calculated. Results Findings indicate that women with advanced maternal age showed an increased probability of giving birth to low birth weight infants. Conversely, mothers aged below < 30 years had an elevated risk for high birth weight infants. When considering maternal migratory status, the findings were mixed. On one hand, foreign-born mothers showed a higher likelihood of delivering infants with high birth weight; on the other, they displayed a lower risk of low birth weight among newborns in comparison to Spanish natives. Conclusions The study addresses two key aspects. First, it highlights the increased risk of low birth weight in mothers delivering at an advanced age. Second, it emphasizes the importance of accounting for maternal migratory status when investigating the association between age at birth and birth weight outcomes among immigrant mothers. (AU)

Objetivo Examinar si la edad materna avanzada (>40 años) está relacionada con una mayor probabilidad de bajo o alto peso al nacer en los nacidos de madres inmigrantes y nativas en España. Método Se utiliza una base de datos novedosa proporcionada por el Instituto Nacional de Estadística de España que vincula el Censo de 2011 con información sobre nacimientos individuales (2011-2015) de las Estadísticas Vitales (Movimiento Natural de la Población). Los modelos de regresión logística multinomial se utilizaron para estimar la posible asociación entre la edad materna y la probabilidad de bajo o alto peso en los nacidos. Se calcularon predicciones ajustadas promedio para el peso bajo, alto y adecuado según el origen y la edad materna. Resultados La edad materna avanzada se asocia con una mayor probabilidad de bajo peso en los nacidos. Por el contrario, las madres menores de 30 años presentan un riesgo elevado de tener bebés con alto peso. Sin embargo, al considerar el origen materno, los resultados fueron mixtos. Por un lado, las madres nacidas en el extranjero mostraron una mayor probabilidad de nacidos con alto peso; por otro, presentaron un menor riesgo de bajo peso en los nacidos. Conclusiones El estudio destaca dos aspectos clave. En primer lugar, pone de relieve el mayor riesgo de bajo peso al nacer en las madres que dan a luz a una edad avanzada. En segundo, la importancia de tener en cuenta el estatus migratorio materno en la asociación entre la edad materna y el peso al nacer. (AU)

Intergenerational transmission of fertility in Spain among cohorts born during the first half of twentieth century.

It is known that historically fertility is correlated between generations of the same family. These links tend to be explained either in terms of the biogenetic determinants of reproduction or by the transmission of intra-familial values associated with reproduction and family life. Less is known about the micro-determinants of these links or about the extent to which the progressive modernization of reproductive outcomes over the past century has affected behavior. In this paper, we will address these issues for Spain with data from the Socio-Demographic Survey (SDS) carried out in 1991 and including data on cohorts born between 1900 and 1946. These data enable us to explore the micro determinants of fertility at different points of time during this period. Our results point to the existence of a significant correlation between intergenerational reproductive outcomes that persists and strengthens throughout this period of demographic change. Results confirm the importance of birth order in large family groups where firstborn offspring are more likely to have larger families than subsequent siblings. There is also evidence that the strength of these intergenerational ties increases with the onset of more modern demographic behavior characterized by sharply declining fertility. The results presented here promise to condition future debates on the subject.

Fertility and contraception: The experience of Spanish women born in the first half of the twentieth century.

New data based on retrospective interviews with older informants enable us to review the history of contraceptive use among Spanish women over much of the twentieth century. This source is unique because it includes cohorts of women whose reproductive lives took place before, during, and after the baby boom. Traditional contraceptive methods (withdrawal and periodic abstinence) were central to the experience of the first set of women, while the last set made full use of modern as well as some traditional methods. For the first cohorts, traditional methods spearheaded the historic decline in fertility, while among the last set of women modern methods led to a precipitous decline towards the below-replacement fertility that continues in Spain today. There is no evidence that the modest increases in fertility during the baby boom in Spain were the result of a decline in the use of contraception among married women.

Partnership, living arrangements, and low birth weight: evidence from a population-based study on Spanish mothers.

BACKGROUND: Birth weight is considered a crucial indicator of individual and population health, as it determines a newborn's growth and development. An extensive body of research has explored various determinants of perinatal health, including the impact of living arrangements. This population-based study analyzes the relationship between mothers' partnership status and household structure and children's low birth weights. It addresses two basic research objectives: on one hand, how living/not living in a couple affects birth weight; on the other, how partnership status impact on birthweight when mothers live in extended households with other non-nuclear members. METHODS: A novel database provided by the Spanish Office for National Statistics (INE), which links the 2011 census with births registered from 2011 to 2015 (sample size 22,433) is used. Llogistic regression models are estimated tto obtain adjusted odds ratios (OR) for the relative effects of living arrangements and other covariates such as characteristics of births and mothers' socioeconomic profiles, on birth weight. RESULTS: Differences in low-birth-weight rates may be attributed to the dissimilar socio-demographic characteristics of the groups of mothers in the different coresidential situations. Although our models revealed that the impact of the covariates on birth weight was similar to that shown by previous studies, this was not the case for the effect of the main explanatory variable. Contrary to expectations, the presence/absence of a male partner in nuclear or in extended households does not reveal significant protection against low birth weight. Children born in households in which the male partner was absent were not more likely to have a low birth weight. On the other hand, analyzing the possible protective effect of extended households, we did not detect significant differences in the likelihood of low birth weight between single mothers without and with non-nuclear coresidents in their households. CONCLUSIONS: Our analysis provides novel evidence regarding the effect of partnership status and household type on perinatal health in Spain. First, contrary to what has been observed in previous studies in Spain and elsewhere, our study shows that living without a partner has no effect on low birth weight. Second, we reveal that households including non-nuclear coresidents are associated with low birth weight suggesting that even in a basically familist societal context such as the Spanish one, the extended family does not fully protect against poor perinatal outcomes.

Spain's Persistent Negative Educational Gradient in Fertility.

A trend towards a reversal of the negative educational gradient in fertility has been detected in some advanced societies, although the end of this inverse relationship is far from being generalized across developed countries. Previous analyses have shown that, for most of the twentieth century, Spain exhibited the steady negative educational gradients in fertility that characterize the low-fertility demographic regimes in Southern Europe. This report presents data collected on the period fertility of Spanish women between 2007 and 2017 and tests for the persistence of educational gradients in their recent reproductive behavior. Using data taken from Spanish administrative registers and standard period indicators of fertility, evidence is offered that proves that a negative educational gradient in fertility continues to exist in the country in accordance with the historical experience of cohorts born during the first decades of the twentieth century. This negative gradient implies significant differences in fertility between educational categories and affects both quantum and tempo. Moreover, the educational differentials in fertility not only persisted during the observed years but probably widened.

Partnership and mortality in mid and late life: Protection or selection?

The main goal of this paper is to address how different partnership statuses impact the likelihood of death among mature adults and elderly persons in Spain circa 2012 using a massive new dataset of administrative registers linked to census data. First, gross and net effects of having a partner on mortality risks of partnered and non-partnered persons are evaluated; then the characteristics and the importance of selection and protection effects of marriage and partnership with regard to the likelihood of death are assessed. We make use of exact matching methods in order to avoid the selection bias associated with the non-random assignment of persons to different partnership statuses. Protection effects decline gradually with age, but always remain positive. Selection effects show a far more pronounced decline with age leading to a pattern in which selection is much stronger than protection during the mature adult ages, but then disappear entirely and even become negative as people age. While both sexes show similar patterns, the protection effect is slightly higher among men while the selection effect is much higher among women, especially before 65 years of age.

Impact of Socio-economic Status on Low Birthweight: Decomposing the Differences Between Natives and Immigrants in Spain.

In this population-based study, we explored the relationships between immigration, socio-economic status (SES), and perinatal outcomes. We quantified the effects of SES on birthweight disparities between native and immigrant mothers in Spain. We obtained birth and SES data from the 2011 census and administrative registers for years 2011-2015. The associations between origin, statuses, and the likelihood of low birthweight were estimated using logistic regressions. Fairlie's nonlinear extension of the Oaxaca-Blinder decomposition method was applied to identify the extent to which the differences in birthweight between groups corresponded to socio-economic composition or to rates. Our results showed that African and Latin American mothers exhibited advantage in the perinatal outcomes over native mothers [odds ratio (OR) 0.75; 95% confidence interval (CI) 0.63-0.90 and OR 0.73; 95% CI 0.65-0.82, respectively]. Decomposition analyses revealed that such advantage was not affected by the lower positions within the socio-economic structure that African and Latin American populations occupied.

Beyond the healthy immigrant paradox: decomposing differences in birthweight among immigrants in Spain.

BACKGROUND: The healthy immigrant paradox refers to the unexpected health advantages of immigrant groups settled in host countries. In this population-based study we analyze immigrant advantages in birthweight decomposing differences between infants born to immigrant mothers from specific origins. METHOD: Using publicly available data from Spanish Vital Statistics for the period 2007-2017, differential birthweights among several groups of immigrants were estimated with an ordinary least squares regression. The Oaxaca-Blinder regression-based decomposition method was then applied to identify the extent to which differences in birthweight between groups corresponded to compositional disparities or to other factors. RESULTS: Our analysis of singleton live births to migrant mothers in Spain between 2007 and 2017 (N = 542,137) confirmed the healthy immigrant paradox for certain immigrant populations settled in Spain. Compared with infants born to mothers from high-income countries, the adjusted birthweight was higher for infants born to mothers from non-high- income European countries (33.2 g, 95% CI: 28.3-38.1, P < 0.01), mothers from African countries (52.2 g, 95% CI: 46.9-57.5, P < 0.01), and mothers from Latin American countries (57.4 g, 95% CI: 52.9-61.3, P < 0.01), but lower for infants born to mothers from Asian non-high-income countries (- 31.4 g, 95% CI: - 38.4 to - 24.3, P < 0.01). Decomposition analysis showed that when compared with infants born to mothers from high-income countries, compositional heterogeneity accounts for a substantial proportion of the difference in birthweights. For example, it accounts for 53.5% (95% CI: 24.0-29.7, P < 0.01) of the difference in birthweights for infants born to mothers from non-high-income European countries, 70.9% (95% CI: 60-66.7, P < 0.01) for those born to mothers from African countries, and 38.5% (95% CI: 26.1-29.3, P < 0.01) for those born to mothers from Latin American countries. CONCLUSIONS: Our results provide strong population-based evidence for the healthy immigrant paradox in birthweight among certain migrant groups in Spain. However, birth outcomes vary significantly depending on the origins of migrant subpopulations, meaning that not all immigrant groups are unexpectedly healthier. A significant portion of the perinatal health advantage of certain immigrant groups is only a by-product of their group composition (by age, parity, marital status, socioeconomic status, and citizenship of mother, age and migratory status of father and type of delivery) and does not necessarily correspond to other medical, environmental, or behavioral factors.

Revisiting mid-twentieth-century fertility shifts from a global perspective.

In the developed world, the historic process of fertility decline was interrupted by an unexpected period of increasing fertility called the baby boom. Recent studies suggest that a similar trend change in fertility may have occurred in many less developed nations at approximately the same time. Using cohort fertility data for 26 less developed countries from around the world taken from the Integrated Public Use Microdata Series, International (IPUMS-I), this paper aims to ascertain the extent to which these trend changes occurred in a large sample of countries around the world. It offers convincing proof of the existence of an upward shift in fertility among cohorts born during the 1930s, which was common to many countries in the less developed world. Despite many similarities with the baby boom, there are also differences stemming, mostly, from its timing with respect to the demographic transition.

Residential status and health in middle and late life: a population-based study with new data from Spain.

OBJECTIVES: To address how different residential situations impact the likelihood of death among mature adults and elderly persons. DESIGN: Population-based study with administrative data linked to census data. SETTING: Spain. PARTICIPANTS: Spanish population alive on 1 January 2012, observed between 1 January 2012 and 31 December 2012. A 10% random sample of the Spanish population, including 2 054 427 person years and 28 736 deaths, is used. MAIN OUTCOME MEASURE: Registered deaths in the 2012 Spanish vital statistics. METHODS: Using a new data set based on linked administrative registers, we estimate unadjusted and adjusted mortality rates by coresidential situation. Differential mortality is measured by rate ratios (RR) estimated with Poisson regression. Cause of death data are used to explore the mechanisms involved in excess mortality by residential status. RESULTS: Compared with men 45-54 living with partners, the risk of death is much higher for those without partners living with others (RR 2.0, 95% CI 1.7 to 2.4) or for those living alone (RR 1.9, 95% CI 1.5 to 2.4). After 84, excess mortality among men living with others persists (RR 1.4, 95% CI 1.3 to 1.5), but disappears for those living alone (RR 1.0, 95% CI 0.9 to 1.1). Both among women 45-64 living with others but without partner (RR 1.8, 95% CI 1.5 to 2.3) and among those living alone (RR 2.2, 95% CI 1.5 to 3.1) the pattern is similar to men. At higher ages, however, excess mortality for women living alone decreases (RR 1.2, 95% CI 1.1 to 1.2), though it persists for women living with others (RR 1.9, 95% CI 1.7 to 2.0). CONCLUSIONS: These findings indicate direct effects of living arrangements on mortality and health-related selection effects influencing residential choices. These effects may be partially affected by age and prevailing societal and cultural contexts.

Childlessness in Twentieth-Century Spain: A Cohort Analysis for Women Born 1920-1969.

Studies of childlessness in the twentieth century in developed countries have underscored the existence of diverging trends with higher levels among cohorts born at the beginning of the twentieth century, lower ones among the baby boom cohorts and finally higher ones for cohorts born after the Second World War. Spain also shows these basic trends, but the fit is not identical to that of other countries, with differences affecting the timing of trend changes and also the levels of childlessness observed in the final part of the period. This paper focuses on Spanish women born 1920 and 1969 and explores the factors characterizing traditional/old childlessness and how these differ from those holding more recently. Using microdata from Spanish Census of 2011, our approach makes use of logistic regression and regression-based decomposition techniques. Change over time, as measured by inter-cohort variations, reveals strikingly different patterns of behaviour characterized by a reversal of the traditional association of childlessness with marital status and educational attainment that takes place in a period of intense and pervasive social change.

Expected Lifetime in Different Employment Statuses: Evidence From the Economic Boom-and-Bust Cycle in Spain.

This article analyses the impact of the recent economic crisis on the expected time spent in different employment statuses in Spain. Using data from the Economically Active Population Survey and life tables, we estimate the expected time in work, unemployment, retirement, and other types of economic inactivity during the economic boom-and-bust cycle. Differences in expected years of life spent in different employment statuses are decomposed into effects of mortality and employment behavior. Our results show that men's working life expectancy is much more exposed to economic fluctuations. The impact of the ebbs and flows of the business cycle among women is mitigated by the long-term female trend of growing participation in the labor market associated with the increasing educational attainment of women. In addition, the improvement in mortality only partially contributes to gains in time spent in each status, while the main effects correspond to changes in labor market participation.

Seeding the gender revolution: Women's education and cohort fertility among the baby boom generations.

In Europe and the United States, women's educational attainment started to increase around the middle of the twentieth century. The expected implication was fertility decline and postponement, whereas in fact the opposite occurred. We analyse trends in the quantum of cohort fertility among the baby boom generations in 15 countries and how these relate to women's education. Over the 1901-45 cohorts, the proportion of parents with exactly two children rose steadily and homogeneity in family sizes increased. Progression to a third child and beyond declined in all the countries, continuing the ongoing trends of the fertility transition. In countries with a baby boom, and especially among women with post-primary education, this was compensated for by decreasing childlessness and increasing progression to a second child. These changes, linked to earlier stages of the fertility transition, laid the foundations for later fertility patterns associated with the gender revolution.

Elderly women living alone in Spain: the importance of having children.

Our goal in this paper is to analyse the extent to which completed fertility, and in particular childlessness, is a valid predictor of living alone at advanced ages, an increasingly important residential option in advanced societies with crucial implications for social policy design and the organization of welfare services. Based on micro-data from the 2011 Spanish population census, logistic regression techniques are used to assess the impact of fertility on living alone among elderly women net the effect of age, marital status, educational attainment, and other standard population controls. Our results show a clear relationship between completed fertility and living alone. Childlessness is strongly associated with living alone, while having offspring acts as a powerful buffer against living alone, particularly in larger families. A relevant conclusion of this study is that a growing deficit of family resources available for the elderly women will take place in those societies where low fertility and high rates of childlessness have prevailed in recent decades, leading to substantial growth in the number of childless elderly women and in the incidence of living alone during later life.

Taxonomic complexity in the halophyte Limonium vulgare and related taxa (Plumbaginaceae): insights from analysis of morphological, reproductive and karyological data.

BACKGROUND AND AIMS: Limonium is a well-known example of a group of plants that is taxonomically complex due to certain biological characteristics that hamper species' delineation. The closely related polyploid species Limonium vulgare Mill., L. humile Mill. and L. narbonense Mill. are defined species and can be used for studying patterns of morphological and reproductive variation. The first two taxa are usually found in Atlantic Europe and the third in the Mediterranean region, but a number of intermediate morphological forms may be present alongside typical examples of these species. This study attempts to elucidate morphological, floral and karyological diversity representative of these taxa in the Iberian Peninsula. METHODS: The extent of morphological differentiation was tested through comparison of 197 specimens from both Portugal and Spain using 17 descriptive morphological characters and 19 diagnostic morphometric characters. Analyses of floral morphisms (heterostyly and pollen-stigma dimorphism) and karyological determinations were also conducted. KEY RESULTS AND CONCLUSIONS: Discriminant analysis using morphometric variables reliably assigned individuals in natural populations to their respective groups. In addition, the results provide the first direct evidence that L. narbonense and a new species, LIMONIUM MARITIMUM: Caperta, Cortinhas, Paes, Guara, Espírito-Santo and Erben, SP NOV: , related to L. vulgare are present on Portuguese coasts. Most of these species are found together in mixed populations, especially L. vulgare and L. narbonense. It is hypothesized that taxonomic biodiversity found in sites where distinct species co-occur facilitates the evolutionary processes of hybridization, introgression and apomixis. This study therefore contributes to the elucidation of the taxonomic diversity in L. vulgare-related species and may also help in implementing future conservation programmes to maintain the evolutionary processes generating biodiversity.

Phylogenetics of Anthyllis (Leguminosae: Papilionoideae: Loteae): Partial incongruence between nuclear and plastid markers, a long branch problem and implications for morphological evolution.

Phylogenetic relationships in the genus Anthyllis (Leguminosae: Papilionoideae: Loteae) were investigated using data from the nuclear ribosomal internal transcribed spacer regions (ITS) and three plastid regions (psbA-trnH intergenic spacer, petB-petD region and rps16 intron). Bayesian and maximum parsimony (MP) analysis of a concatenated plastid dataset recovered well-resolved trees that are topologically similar, with many clades supported by unique indels. MP and Bayesian analyses of the ITS sequence data recovered trees that have several well-supported topological differences, both among analyses, and to trees inferred from the plastid data. The most substantial of these concerns A. vulneraria and A. lemanniana, whose placement in the parsimony analysis of the ITS data appears to be due to a strong long-branch effect. Analysis of the secondary structure of the ITS1 spacer showed a strong bias towards transitions in A. vulneraria and A. lemanniana, many of which were also characteristic of certain outgroup taxa. This may contribute to the conflicting placement of this clade in the MP tree for the ITS data. Additional conflicts between the plastid and ITS trees were more taxonomically focused. These differences may reflect the occurrence of reticulate evolution between closely related species, including a possible hybrid origin for A. hystrix. The patterns of incongruence between the plastid and the ITS data seem to correlate with taxon ranks. All of our phylogenetic analyses supported the monophyly of Anthyllis (incl. Hymenocarpos). Although they are often taxonomically associated with Anthyllis, the genera Dorycnopsis and Tripodion are shown here to be more closely related to other genera of Loteae. We infer up to six major clades in Anthyllis that are morphologically well-characterized, and which could be recognized as sections. Four of these agree with various morphology-based classifications, while the other two are novel. We reconstruct the evolution of several morphological characteristics found only in Anthyllis or tribe Loteae. Some of these characters support major clades, while others show evidence of homoplasy within Anthyllis.

Eficacia de la glibenclamida con metformina en el control de la glicemia en pacientes con diabetes mellitus tipo 2 / Effectiveness of glibenclamida with metformina in the check of glicemia in patients with diabetes mellitus type 2

Para evaluar la glicemia de la combinación glibenclamida-metformina en pacientes diabéticos con diabetes mellitus tipo 2 que no lograron el control glicémico con glibenclamida sola, se realizó un estudio longitudinal en 138 pacientes diabéticos del Hospital I Luis Albrecht EsSalud de Trujillo. El promedio de edad fue 58,1 (+ DE 9,14 años) y el índice de masa corporal (28,32 (+ DE 4,17 kg/m²). Se administró la combinación glibenclamida (5 a 10 mg/día) más metformina (850 a 1700 mg/día). El control glicémico a los tres meses de tratamiento con la combinación se logró en 30, 43 por ciento de pacientes según el criterio de la glucosa de ayuno y en 42,03 por ciento sgún el criterio de la HbA1c. La terapia con la combinación glibenclamida-metformina permitió reducir el valor promedio de glicemia de ayuno de 219,71 mg/dL (+DE 56,07) a 164,22 mg/dL (+De=53,53)( p < 0,01), y la HbA1c de 9,03 por ciento (+ DE=1,35) a 7,99 por ciento (+ DE=1,89) (p< 0,01). Además, se logró una reducción del peso de los pacientes a los tres meses de 71,48 kg (+ DE = 11,33) a 68,90 kg (+DE = 11,40) ( p < 0,01). Se concluye que la combinación glibenclamida-metformina es eficaz para mejorar el control de glicemia de los pacientes con diabetes mellitus tipo 2 que no habían logrado un control adecuado con la sulfonilurea sola. Además posterga el empleo de insulina por lo que, probablemente, reduce costos y la utilización de recursos.