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Penn, Notre Dame Researchers Mapping Genetic History of the Caribbean
Penn Nursing Research Highlighted in Major Study on Human Breast Milk
Penn IUR White Paper: Tracking and Explaining Neighborhood Socio-Economic Change in U.S. Metropolitan Areas between 1990 and 2010
Penn, Notre Dame Researchers Mapping Genetic History of the Caribbean
In the island chain called the Lesser Antilles, stretching from the Virgin Islands south to Trinidad and Tobago, a team of researchers led by Theodore Schurr, an anthropology professor in the University of Pennsylvania’s School of Arts & Sciences, is solving a generations-old mystery: do indigenous communities still exist in the Caribbean region today?
“We’re really trying to connect the dots and understand the migration, the flow of people in and out of the region,” said Dr. Schurr, who has worked in the area since 2012 and on similar genetics projects for more than two decades. “Each island seems to have its distinct history.”
Dr. Schurr and his team, which includes Jill Bennett Gaieski of Penn’s Perelman School of Medicine, Miguel Vilar, a Penn postdoc at the time of the research and now at the National Geographic Society and Jada Benn Torres of Notre Dame University, focused their research on DNA samples from 88 participants in the First Peoples Community in Trinidad and the Garifuna people in St. Vincent. By looking at mitochondrial DNA, Y-chromosomes and autosomal markers, three parts of the genome known for containing what Dr. Schurr described as “signals” of indigenous ancestry, the researchers eventually detected 42% indigenous ancestry from the maternal side, 28% from the paternal side.
Mitochondrial DNA comes from the mother only, regardless of the number of generations considered. The Y-chromosome is the paternal correlate, or the complement to mitochondrial DNA, passed from fathers to sons. Autosomes, only recently included in this area of research, do not reveal specific details about maternal and paternal lineage but give an overall picture of the genetic contributions from ancestors traced through both the mother’s and father’s sides of the family. “In the case of the mitochondrial DNA and the Y-chromosome,” Dr. Schurr said, “we know the markers that define those lineages commonly seen in indigenous populations of the Americas.”
During the past three years, he and his colleagues have done fieldwork in St. Vincent and Trinidad. “These communities are not passive in this whole process; they’re actively exploring their own ancestry,” he added. “They’re also trying to establish the fact that they have indigenous ancestry, that they are the descendants of the original inhabitants. They’re reclaiming that history.”
The work began as part of the Genographic Project, which was started and initially funded by the National Geographic Society. It is a multi-institutional endeavor with the goal of mapping the globe genetically. A dozen research labs around the world analyzed DNA samples from indigenous and traditional communities, and a public participation component of the project allowed anyone to submit DNA for analysis in the database. Dr. Schurr’s contribution involved indigenous communities of the Americas.
Expanding into parts of the Caribbean made sense. “It was an opportunity to actually add new information about an area that is relatively well described archaeologically, but not so much so genetically,” he said.
Dr. Schurr has already completed a similar study in Puerto Rico and recently began a larger project in the Dominican Republic.
Research for the Genographic Project has been taking place since 2005. The first phase, funded by the National Geographic Society, IBM and the Waitt Family Foundation, ended in 2012 after completion of significant field research and laboratory analysis around the world. The second phase, supported by the University of Pennsylvania, the Institute for Scholarship and Learning at Notre Dame and the National Geographic Society, has allowed for targeted field research and the expanded use of autosomal markers to help elucidate the genetic history of human populations.
Dr. Schurr and his collaborators published their recent work about genetic diversity in the Lesser Antilles in the journal PLOS ONE.
Penn Nursing Research Highlighted in Major Study on Human Breast Milk
Data from a study authored by Eileen T. Lake, the Jessie M. Scott Endowed Term Chair in Nursing and Health Policy and associate professor of sociology and associate director of Penn’s Center for Health Outcomes and Policy Research (CHOPR), was used in a recent investigation published in the International Journal of Nursing Studies (IJNS), which found that breastfeeding support by nurses and better work environments for nurses increase rates of babies in neonatal intensive care units (NICU) being discharged home on breast milk rather than formula. Dr. Lake’s study was funded by the Robert Wood Johnson Foundation Interdisciplinary Nursing Quality Research Initiative (INQRI).
The IJNS study also revealed that nurses with higher education levels (at least a BSN) and those who work in units that are adequately staffed discharge more babies on breast milk. NICUs with better work environments that allow nurses time and resources, have more supportive nurse managers and encourage more collaborative working relationships between nurses and doctors further enhance nurses’ ability to provide breastfeeding support, which significantly increases the percentage of infants who receive breast milk.
The IJNS study was led by Sunny Hallowell, currently an assistant professor at Villanova University’s School of Nursing. Dr. Hallowell was a postdoctoral fellow at CHOPR. The research team conducted secondary analysis of INQRI-funded nurse survey data from 5,614 nurses and breast milk discharge rates in 97 NICUs. These units cared for 6,997 infants with very low birth weights (between 501 and 1500 grams at birth). The NICUs were part of the Vermont Oxford Network, a NICU quality improvement collaborative. Several other factors, including the presence of lactation consultants, did not have a significant impact on the proportion of infants discharged on breast milk.
“Breastfeeding support by registered nurses had the largest impact on whether infants were receiving breast milk at discharge. However, nursing unit factors—notably education levels and good work environment—also produced higher rates of breast milk at discharge,” said Dr. Lake. “Our findings speak to the importance of hospitals investing in better work environments and better educated nurses to increase the rate of infants discharged on breast milk, which provides them with the best nutritional care and the healthiest start in life.”
Other members of the research team were Jeannette Rogowski, university professor in health economics in the department of health systems & policy at the Rutgers School of Public Health; Diane Spatz, professor of perinatal nursing and Helen M. Shearer Term Professor of Nutrition at Penn; Alexandra Hanlon, research professor of nursing at Penn; and Michael Kenny, public health analyst in the Vermont Department of Health.
Penn IUR White Paper: Tracking and Explaining Neighborhood Socio-Economic Change in U.S. Metropolitan Areas between 1990 and 2010
City living is back. After half a century of relentless population decline and several false starts at revitalization, residential investment in America’s urban centers began to pick up in the mid-1990s. In the ten years between the 2000 and 2010 decennial censuses, the housing stock in America’s 50 largest central cities grew by 1.5 million dwelling units, or 8.3%. As the Environmental Protection Agency has documented in a series of reports, this “back-to-the-city” construction trend continued even through the Great Recession.
According to John D. Landis, the Crossways Professor of City & Regional Planning in the School of Design at Penn, multiple factors underlie this boomlet. Members of the millennial generation (those born between 1982 and 2004) proved themselves less interested than prior generations in getting married, having children and moving to the suburbs. Urban crime rates fell significantly. Suburban highways became as congested as their urban counterparts. Pushed by successive presidential administrations and Congress, low-cost mortgage money grew more available to moderate-income and minority residents of older neighborhoods, enabling many of them to become homeowners. Between 2000 and 2008, the number of homeowners in America’s 50 largest central cities rose by 0.6 million, pushing the homeownership rate to an all-time high of just under 50%.
Dr. Landis noted in his White Paper that not everyone greeted these changes favorably. Newspaper articles appeared in city after city citing the rising incidence of gentrification—a form of neighborhood change wherein developers and higher-income households buy up residential properties in low-income neighborhoods for the purpose of inhabiting them, upgrading them, renting them out at a higher rent, or, in some cases, just flipping them. The purported end result is the displacement of long-time and usually poorer residents.
Residential upgrading was hardly limited to urban cores. Homebuilders were also hard at work in suburban communities and at the peri-urban edge building millions of large single-family homes. These “McMansions,” as they were known, were typically larger than 3,000 square feet and included garage space for three cars. Just as urban upgrading was drawing popular criticism as gentrification, suburban upgrading was drawing comparable attacks for being unsustainable and contributing to sprawl.
Of course, not everyone was lucky enough to live in an improving or even stable neighborhood. Behind the newspaper headlines and websites protesting gentrification and McMansion development, large numbers of urban and suburban residents continued living in neighborhoods where public and private investment had failed to keep pace with the ravages of time, depopulation or economic decline. Not until the subprime mortgage bubble finally popped in 2008 did the vulnerability of both urban and suburban neighborhoods to macro-economic forces and financial policies finally become clear.
The Penn IUR Policy Brief is at http://penniur.upenn.edu/uploads/media/PennIUR-Policy-Brief-Landis.pdf
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