Migration

The pioneering work of Ödegaard (1932) was the first to link migration and
schizophrenia by reporting rates in Norwegian immigrants in Minnesota as twice that of
native Minnesotans and of Norwegians in Norway. However, only in recent decades has
an interest in migration and schizophrenia been rekindled as a result of reports of elevated
rates of schizophrenia in Afro-Caribbean immigrants in the United Kingdom in the mid-
1960s (Hutchinson & Haasen, 2004). Later studies reported elevated rates in secondgeneration
Afro-Caribbean immigrants compared to first-generation (Harrison, Owens,
Holton, Neilson, & Boot, 1988).
In the United States, Blacks were diagnosed with schizophrenia 2.4 times more
often than Whites (Olbert, Nagendra, & Buck, 2018). However, mental health researchers
in the United States generally combine all individuals of African descent as African-
Americans. This practice obscures the nuances of culture and ethnicity within the Black
subgroups as well as the immigrant status of Afro-Caribbeans. This research focused on the Afro-Caribbean immigrants and factors that predict risk for schizophrenia within this
population.
The process of migration is a complex enterprise that produces stressors and
challenges, the effects of which are multifaceted. The social and environmental forces
that parallel the process of migration may predispose individuals to severe psychiatric
disorders such as schizophrenia. Socio-political dynamics in the host country that
marginalize others of different cultural and/or racial persuasions can compound the
negative effects of post-migration. Therefore, migration is considered a social
determinant of health.
Empirical evidence has substantiated that socio-environmental factors such as
urbanicity, discrimination or socio-economic deprivation, social support, and goal
striving stress are potential contributing factors to the development of psychotic disorders
in immigrants. Moreover, evidence has supported that the darker the skin color of the
immigrant the greater the risk (Cantor-Graae, 2007). The findings of this study confirmed
that for Afro-Caribbean immigrants stressors in the post-migration phase such as
discrimination, limited social support, and economic hardship that can be compounded by
the number of dependent children were identified as possible predictors of risk for
schizophrenia. This risk increased with length of residency and continued into the
second-generation.

Recent studies show that sea turtles use both magnetic and visual cues to successfully orient. Juvenile green sea turtles from the near shore reefs of Palm Beach County, Florida were brought to the lab to determine whether the sun could serve as a visual orientation cue. When tethered during the day in a large outdoor tank west of the ocean, the turtles oriented east to northeast. To determine whether the sun's position was used to maintain their heading, I altered the turtles' perception of time by entraining them to a light cycle advanced by 7 h relative to the natural cycle. When tested afterward in the same outdoor tank the turtles oriented northwest, the predicted direction after compensating for the sun's movement over 7 h across the sky. Orientation was unchanged when the turtles bore magnets that negated the use of magnetic cues. These results are consistent with the hypothesis that the turtles used the sun for orientation.

Loggerhead sea turtles nest on either the Atlantic or Gulf coast of Florida. The hatchlings from these nests migrate offshore in opposite directions. The purpose of my study was to determine if Gulf coast hatchlings use magnetic maps, as Atlantic coast hatchlings do, both to locate areas favorable for survival in the Gulf of Mexico and to orient appropriately within surface currents that could transport them into the Atlantic Ocean. To find out, I presented Gulf coast hatchlings with magnetic fields corresponding to different locations inside the Gulf, and within currents leading into (Florida Straits) and within (Gulf Stream) the western portion of the Atlantic Ocean. I conclude that Gulf coast hatchlings (i) use a high resolution magnetic map for navigation within the Gulf of Mexico, (ii) initially remain within the eastern Gulf, but later may (iii) gain entry into currents that transport them into Atlantic waters.

There are four distinct subpopulations of loggerhead sea turtles (Caretta caretta) in Florida as determined behaviorally by geographic fidelity, and genetically by mitochondrial haplotypes. The South Florida subpopulation consists of females nesting on the southeastern and southwestern coasts of Florida and their offspring. Previous research shows that west coast hatchlings exhibit higher levels of nocturnal swimming during the postfrenzy period than east coast hatchlings. This study attempted to determine how these differences in migratory behavior develop. A reciprocal translocation experiment was conducted to distinguish between environmental and genetic factors. No consistent differences in hatchling swimming behavior were seen based on geography. Movement of nests resulted in lower levels of nocturnal swimming behavior in hatchlings compared to hatchlings that emerged from natural nests, suggesting that the relocation of nests may not provide a natural incubation environment for developing hatchlings.