26 research outputs found
Finishing the euchromatic sequence of the human genome
The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead
Migración internacional: ¿Sustituto de la seguridad social?
Migración internacional: ¿Sustituto de la seguridad social
International monetary transfers: Three essays on migrant decision-making
This dissertation consists of three essays on migrant transfers. In the first essay, based on the theoretical rationale of new economics of labor migration, I show that family structure and degree of market development play important roles in explaining remitting behavior among Mexican, Dominican and Puerto Rican migrants. These factors shape international migration in a way that determine a specific profile of the heavy remitter: a male laborer of low educational attainment, who is in the United States for a short term and who typically works long hours in a seasonal job in order to accumulate extra-savings to send home. The same factors, however, do not help to understand remittances among presumably settled migrants. Hence, in the second essay I elaborate a remittance narrative for presumably settled migrants based on the transnational migration paradigm. I postulate that a male migrant\u27s remitting behavior will be positively associated with the fall in social status that he experiences in the United States. An empirical test, however, provided little support for this idea. A fall in occupational prestige and a decline in patriarchal authority do not motivate remitting behavior among male migrants from the three countries understudy. Instead, I find that structural conditions in the communities of origin of the migrants influence their remitting behavior, irrespective of their situation in the United States, consistent with predictions from the new economics of labor migration. My third essay draws a parallel with an idea developed by fertility theorists that postulates an old-age security incentive for high fertility in developing countries. Similarly, I propose that migration may operate as a strategy to secure retirement. My empirical analysis on Mexican migrants to the United States gives strong support to this idea: those who hold informal jobs are much more likely to migrate than those whose jobs are covered by the Mexican social security system. In addition, among the Mexican elderly, those with migration experience are more likely to hold a pension. Longer US experience systematically increases this likelihood. Since social security is one more type of insurance my contribution readily aligns with the new economics of labor migration, adding one more market to the list previously developed by migration theorists
International monetary transfers: Three essays on migrant decision-making
This dissertation consists of three essays on migrant transfers. In the first essay, based on the theoretical rationale of new economics of labor migration, I show that family structure and degree of market development play important roles in explaining remitting behavior among Mexican, Dominican and Puerto Rican migrants. These factors shape international migration in a way that determine a specific profile of the heavy remitter: a male laborer of low educational attainment, who is in the United States for a short term and who typically works long hours in a seasonal job in order to accumulate extra-savings to send home. The same factors, however, do not help to understand remittances among presumably settled migrants. Hence, in the second essay I elaborate a remittance narrative for presumably settled migrants based on the transnational migration paradigm. I postulate that a male migrant\u27s remitting behavior will be positively associated with the fall in social status that he experiences in the United States. An empirical test, however, provided little support for this idea. A fall in occupational prestige and a decline in patriarchal authority do not motivate remitting behavior among male migrants from the three countries understudy. Instead, I find that structural conditions in the communities of origin of the migrants influence their remitting behavior, irrespective of their situation in the United States, consistent with predictions from the new economics of labor migration. My third essay draws a parallel with an idea developed by fertility theorists that postulates an old-age security incentive for high fertility in developing countries. Similarly, I propose that migration may operate as a strategy to secure retirement. My empirical analysis on Mexican migrants to the United States gives strong support to this idea: those who hold informal jobs are much more likely to migrate than those whose jobs are covered by the Mexican social security system. In addition, among the Mexican elderly, those with migration experience are more likely to hold a pension. Longer US experience systematically increases this likelihood. Since social security is one more type of insurance my contribution readily aligns with the new economics of labor migration, adding one more market to the list previously developed by migration theorists
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Patterns of U.S. Migration from Mexico, the Caribbean, and Central America
Se comparan datos de las encuestas Latin American Migration Project (lamp) y Mexican Migration Project (mmp) para analizar patrones migratorios a los Estados Unidos desde México, Puerto Rico, República Dominicana, Nicaragua y Costa Rica. Usando muestras de 31 comunidades, se documenta la frecuencia y tiempos de migración, la fecha, duración, destino y documentación del primer y más reciente viaje a los Estados Unidos, las caracterÃsticas laborales de los migrantes en estos viajes, y las caracterÃsticas socieconómicas y la selectividad de los migrantes. Los resultados muestran que una proporción significativa de la migración es indocumentada. Las caracterÃsticas distintivas de la migración mexicana con respecto a otros flujos son su concentración en el trabajo agrÃcola, la falta de selectividad educativa, la mayor frecuencia de los viajes y tiempos de estancia más cortos. Todos los grupos muestran una pronunciada tendencia a establecerse lejos de las áreas de destino tradicionales. El análisis sugiere patrones y procesos de migración comunes, estructurados y expresados en maneras distintas de acuerdo al contexto. Este análisis muestra que los datos del lamp y del mmp pueden conjugarse con efectividad para llevar a cabo estudios cuantitativos comparativos
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Patterns of US Migration from Mexico, the Caribbean, and Central America
Data from the Latin American Migration Project (LAMP) and the Mexican Migration Project (MMP) is combined to analyze migration patterns for Mexico, Puerto Rico, the Dominican Republic, Nicaragua, and Costa Rica. Drawing on samples of 31 communities, we document the frequency and timing of migration, the date, duration, destination, and documentation of the first and the most recent U.S. trips, the employment characteristics of migrants on those trips, and migrants’ socioeconomic characteristics and selectivity. Results show that a significant share of the migration is unauthorized. The distinctive features separating Mexican migration from other flows are its concentration in farm labor, lack of educational selectivity, more frequent trips, and shorter durations of stay. All groups are showing a pronounced tendency to settle away from traditional destination areas. The analysis suggests a commonality of basic patterns and processes of migration structured and expressed in distinct ways according to context. This analysis shows that data from the LAMP and the MMP can be combined effectively to undertake comparative quantitative studies
The Effects of Questionnaire Translation on Demographic Data and Analysis
Questionnaire translation, Standardized interview, Data collection, Field methods, Developing countries, Kenya,
Family Planning for Strangers: An Experiment on the Validity of Reported Contraceptive Use
<div><p>Sterilization levels reported in the Dominican Republic appear well above what we would normally expect given prevailing patterns in the region. We suspect that the use of strangers as interviewers—the normative approach in data collection in both developed and developing country settings—may be partly responsible for this result, and may underlie a long history of bias in family planning data. We present findings from a field experiment conducted in a Dominican town in 2010, where interviewer assignment was randomized by level of preexisting level of familiarity between interviewer and respondent. In our data, sterilization use is higher when the interviewer is an outsider, as opposed to someone known to the respondent or from the same community. In addition, high sterilization use is correlated with a propensity of respondents to present themselves in a positive light to interviewers. These results call into question the routine use of strangers and outsiders as interviewers in demographic and health surveys.</p></div