The Rise and Fall of Income Inequality in Mexico: 1989-2010

Inequality in Mexico rose between 1989 and 1994 and declined between 1994 and 2010. We examine the role of market forces (demand and supply of labour by skill), institutional factors (minimum wages and unionization rate), and public policy (cash transfers) in explaining changes in inequality. We apply the ‘re-centered influence function’ method to decompose changes in hourly wages into characteristics and returns. The main driver is changes in returns. Returns rose (1989-1994) due to institutional factors and labor demand. Returns declined (1994-2006) due to changes in supply and --to a lesser extent--in demand; institutional factors were not relevant. Government transfers contributed to the decline in inequality, especially after 2000.inequality, wages, disposable income, labor markets, Mexico

Teenage Pregnancy in Mexico: Evolution and Consequences

We analyze the consequences of a teenage pregnancy event in the short- and long-run in Mexico. Using longitudinal and cross-section data, we match females who got pregnant and those that did not based on a propensity score. Several balancing tests and specifications indicate that the main assumptions to estimate the average treatment effect on the treated using a propensity score are satisfied. In the short-run, we find that a teenage pregnancy causes a decrease of 0.6-0.8 years of schooling, lower attendance to school, less hours of work and a higher marriage rate. At the household level, we do not find any effect in parental hours of work or income per capita. In the long-run, we find a loss in years of education of 1-1.2 and a higher probability of being married, but also higher probability of being separated or divorced. We also find that household income per capita is lower at least in the long-run.teenage, pregnancy, labor outcomes, propensity score, matching

Evidence for a Putative Isoprene Reductase in Acetobacterium wieringae

Recent discoveries of isoprene-metabolizing microorganisms suggest they might play an important role in the global isoprene budget. Under anoxic conditions, isoprene can be used as an electron acceptor and is reduced to methylbutene. This study describes the proteogenomic profiling of an isoprene-reducing bacterial culture to identify organisms and genes responsible for the isoprene hydrogenation reaction. A metagenome-assembled genome (MAG) of the most abundant (89% relative abundance) lineage in the enrichment, Acetobacterium wieringae, was obtained. Comparative proteogenomics and reverse transcription-PCR (RT-PCR) identified a putative five-gene operon from the A. wieringae MAG upregulated during isoprene reduction. The operon encodes a putative oxidoreductase, three pleiotropic nickel chaperones (2 × HypA, HypB), and one 4Fe-4S ferredoxin. The oxidoreductase is proposed as the putative isoprene reductase with a binding site for NADH, flavin adenine dinucleotide (FAD), two pairs of canonical [4Fe-4S] clusters, and a putative iron-sulfur cluster site in a Cys6bonding environment. Well-studied Acetobacterium strains, such as A. woodii DSM 1030, A. wieringae DSM 1911, or A. malicum DSM 4132, do not encode the isoprene-regulated operon but encode, like many other bacteria, a homolog of the putative isoprene reductase (;47 to 49% amino acid sequence identity). Uncharacterized homologs of the putative isoprene reductase are observed across the Firmicutes, Spirochaetes, Tenericutes, Actinobacteria, Chloroflexi, Bacteroidetes, and Proteobacteria, suggesting the ability of biohydrogenation of unfunctionalized conjugated doubled bonds in other unsaturated hydrocarbons

Reducción de los salarios de los trabajadores con educación universitaria en México: ¿son los más jóvenes o los más viejos los más perjudicados?

A reduction in the wage premium for skilled labor –and a consistent reduction of overall wage inequality-has played an important role in explaining the fall of income inequality in Latin America during the 2000-2014 period. Consistent with that pattern, wage inequality declined in Mexico since 2000. This paper investigates the possible channels on why the wages of high-skilled workers have declined. Using data from Mexican labor surveys for the period between 2000 and 2014, we investigate if the decline was driven by wages declining more sharply for younger or older workers. We find that wages of older workers declined and the decline was more pronounced the older the cohort. This would seem to support the hypothesis that older workers’ skills became obsoleteUna reducción en la prima salarial del trabajo calificado -y una reducción constante de la desigualdad salarial global- ha jugado un papel importante en la explicación de la caída de la desigualdad del ingreso en América Latina durante el período 2000-2014. En consonancia con ese patrón, la desigualdad salarial disminuyó en México desde el año 2000. Este trabajo investiga las posibles causas de por qué los salarios de los trabajadores altamente cualificados han disminuido. Utilizando datos de encuestas sobre el trabajo de México para el periodo 2000- 2014, se investiga si la reducción se debió a una disminución de salarios más acusada para los trabajadores más jóvenes o más viejos. Nos encontramos con que los salarios de los trabajadores de edad se redujeron y el descenso fue más pronunciado cuanto mayor es la cohorte. Esto parece apoyar la hipótesis de que las cualificaciones de los trabajadores de más edad se volvieron obsoleta

Dynamics of long-term colonization of respiratory tract by Haemophilus influenzae in cystic fibrosis patients shows a marked increase in hypermutable strains

The persistence and variability of 188 Haemophilus influenzae isolates in respiratory tract of 30 cystic fibrosis (CF) patients over the course of 7 years was studied. Antibiotic susceptibility testing, DNA fingerprinting, and analysis of outer membrane protein profiles were performed on all isolates. A total of 115 distinct pulsed-field gel electrophoresis profiles were identified. Ninety percent of patients were cocolonized with two or more clones over the studied period. A third of the patients were cross-colonized with one or two H. influenzae strains; 11% of the clones persisted for 3 or more months. Biotype, outer membrane protein profiles, and resistance profiles showed variation along the studied period, even in persisting clones. Four isolates (2.1%) recovered from 3 patients were type f capsulate, with three of them belonging to the same clone. beta-Lactamase production was detected in 23.9% of isolates while 7% of the beta-lactamase-negative isolates presented diminished susceptibility to ampicillin (beta-lactamase-negative ampicillin resistance phenotype). Remarkably, 21.3% of the H. influenzae isolates presented decreased susceptibility to ciprofloxacin, which was mainly observed in persisting clones. Of the H. influenzae isolates from CF patients, 18 (14.5%) were found to be hypermutable in comparison with 1 (1.4%) from non-CF patients (P < 0.0001). Ten patients (33.3%) were colonized by hypermutable strains over the study period. A multiresistance phenotype and long-term clonal persistence were significantly associated in some cases for up to 7 years. These results suggest that H. influenzae bronchial colonization in CF patients is a dynamic process, but better-adapted clones can persist for long periods of time.This work was supported by a research grant from the Fondo de Investigaciones Sanitarias, Ministerio de Sanidad y Consumo, Madrid, Spain (95-98/0364). We are grateful to E. Moguel for his technical assistance and to C. García (Hospital Lozano Blesa, Zaragoza) and J. C. Alados (Hospital Virgen de las Nieves, Granada) for their cooperation

El colectivo logopédico. Una mirada desde la formación inicial y permanente del logopeda

Introduction: the implementation of the collective of speech therapists is a necessity in order to take actions to the opening of the courses of studies and continuing training of professionals in the Logopedics studies.Objective: to analyze the significance of the speech therapists collective for the opening of the study courses and continuing training of these specialists.Methods: a pedagogical study in which theoretical, empirical and statistical methods were used to collect, interpret and process information related to the subject.Results: the study revealed the significance of the speech-language therapists collective for the initial and permanent training of the speech-language specialist through the accomplishment of the following functions: organizational, teaching-methodological, development and research, which favors the improvement of the mother tongue, prevention, diagnosis and comprehensive speech-language along with communication disorders.Conclusions: a didactic-methodological strategy was implemented that identifies the speech therapists collective as a subsystem or basic organizational level of the specialty.Introducción: el funcionamiento del colectivo logopédico constituye una necesidad para dar respuesta a la formación inicial y permanente de los profesionales de la carrera Logopedia.Objetivo: analizar la pertinencia del colectivo logopédico para la formación inicial y permanente del logopeda.Métodos: estudio de corte pedagógico donde se utilizaron métodos del nivel teórico, empírico y estadístico que permitieron recopilar, interpretar y procesar la información relacionada con la temática.Resultados: el estudio reveló la pertinencia que presenta el colectivo logopédico para la formación inicial y permanente del logopeda mediante el cumplimiento de las funciones: organizativa, docente-metodológica, superación e investigación, lo que favorece el desarrollo de la lengua materna, la prevención, el diagnóstico y la atención logopédica integral de los trastornos del lenguaje y la comunicación.Conclusiones: se implementó una estrategia didáctico-metodológica que identifica el colectivo logopédico como subsistema o nivel organizativo de base de la especialidad de Logopedia.

Bayesian regression models outperform partial least squares methods for predicting milk components and technological properties using infrared spectral data

The aim of this study was to assess the performance of Bayesian models commonly used for genomic selection to predict "difficult-to-predict" dairy traits, such as milk fatty acid (FA) expressed as percentage of total fatty acids, and technological properties, such as fresh cheese yield and protein recovery, using Fourier-transform infrared (FTIR) spectral data. Our main hypothesis was that Bayesian models that can estimate shrinkage and perform variable selection may improve our ability to predict FA traits and technological traits above and beyond what can be achieved using the current calibration models (e.g., partial least squares, PLS). To this end, we assessed a series of Bayesian methods and compared their prediction performance with that of PLS. The comparison between models was done using the same sets of data (i.e., same samples, same variability, same spectral treatment) for each trait. Data consisted of 1,264 individual milk samples collected from Brown Swiss cows for which gas chromatographic FA composition, milk coagulation properties, and cheese-yield traits were available. For each sample, 2 spectra in the infrared region from 5,011 to 925cm(-1) were available and averaged before data analysis. Three Bayesian models: Bayesian ridge regression (Bayes RR), Bayes A, and Bayes B, and 2 reference models: PLS and modified PLS (MPLS) procedures, were used to calibrate equations for each of the traits. The Bayesian models used were implemented in the R package BGLR (http://cran.r-project.org/web/packages/BGLR/index.html), whereas the PLS and MPLS were those implemented in the WinISI II software (Infrasoft International LLC, State College, PA). Prediction accuracy was estimated for each trait and model using 25 replicates of a training-testing validation procedure. Compared with PLS, which is currently the most widely used calibration method, MPLS and the 3 Bayesian methods showed significantly greater prediction accuracy. Accuracy increased in moving from calibration to external validation methods, and in moving from PLS and MPLS to Bayesian methods, particularly Bayes A and Bayes B. The maximum R(2) value of validation was obtained with Bayes B and Bayes A. For the FA, C10:0 (% of each FA on total FA basis) had the highest R(2) (0.75, achieved with Bayes A and Bayes B), and among the technological traits, fresh cheese yield R(2) of 0.82 (achieved with Bayes B). These 2 methods have proven to be useful instruments in shrinking and selecting very informative wavelengths and inferring the structure and functions of the analyzed traits. We conclude that Bayesian models are powerful tools for deriving calibration equations, and, importantly, these equations can be easily developed using existing open-source software. As part of our study, we provide scripts based on the open source R software BGLR, which can be used to train customized prediction equations for other traits or populations

The Role of Emotions on Risk Aversion: A prospect theory experiment

This study measures risk and loss aversion using Prospect Theory and the impact of emotions on those parameters. Our controlled experiment at two universities in Mexico City, using uncompensated students as research subjects, found results similar to those obtained by Tanaka et al. (2010). In order to study the role of emotions, we provided subjects with randomly varied information on rising deaths due to drug violence in Mexico and also on youth unemployment. In agreement with previous studies, we find that risk aversion on the gains domain decreases with age and income. We also find that loss aversion decreases with income and is less for students in public universities. With regard to emotions, risk aversion increases with sadness and loss aversion is negatively influenced by anger. On the loss domain, anger dominates sadness. On average, anger reduces loss aversion by half