1987 — 1991 |
Ebbesson, Sven |
N/AActivity Code Description: No activity code was retrieved: click on the grant title for more information |
Development of Neural Circuits @ University of Alaska Fairbanks Campus
The overall objective of this project is to find and define the processes in the evolution of the nervous system and to determine the relationship between the evolutionary history of a structure or system to normal and abnormal development. The hope is that insights into the evolutionary mechanisms will also elucidate interspecific variability of brain organization, which in turn may provide structure-function correlation. More importantly, the studies may elucidate what evolutionary and ontogenetic constraints determine what synapses are possible between neurons and which are not. Since evidence about the evolution of circuitry cannot be obtained from fossils, Dr. Ebbesson designed an approach to study brain evolution 20 years ago that involves a systematic examination of a given neural system in the broadest possible spectrum of vertebrates with the hope that principles of evolution would emerge from the pattern of the data. The initial objectives have now been reached in that the basic organization and variability of several sensory systems, including the ascending spinal and the visual systems in representative samples of most major vertebrate groups, are now known. The many pathways discovered and described during the last 20 years by a number of investigations point to several operational evolutionary strategies. One of these has been described as the parcellation theory which states that diffuse, undifferentiated, overlapping neural systems existed in the beginning of vertebrate evolution and that during evolution of complex behaviors, and analytical capacities related to these behaviors, a range of neural systems evolved, not by de novo appearance or one system invading another, but by a process of segregation and isolation (parcellation) that involves the formation of more isolated subcircuits by the selective loss of connections. The resultant daughter systems individually lack one or more connections of their ancestors. The evolutionary process is thought to be reflected in the normal ontogenetic development of a given system where a similar segregation- isolation process take place. The objective of Dr. Ebbesson for the next three years is to test and define this theory by defining connections more precisely in the sensory pathways in species from three vertebrate classes that are likely to have extensive overlap of systems; i.e., unparcellated systems. These animals include the bowfin, the nurse shark, and the tiger salamander.
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0.915 |
1987 — 1991 |
Ebbesson, Sven O |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. R55Activity Code Description: Undocumented code - click on the grant title for more information. |
Neuronal Plasticity and Thyroid Hormone @ University of Alaska Fairbanks
This is a Shannon Award providing partial support for research projects that fall short of the assigned institute's funding range but are in the margin of excellence. The Shannon award is intended to provide support to test the feasibility of the approach; develop further tests and refine research techniques; perform secondary analysis of available data sets; or conduct discrete projects that can demonstrate the PI's research capabilities or lend additional weight to an already meritorious application. Further scientific data for the CRISP System are unavailable at this time.
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0.936 |
1991 |
Ebbesson, Sven O |
R21Activity Code Description: To encourage the development of new research activities in categorical program areas. (Support generally is restricted in level of support and in time.) |
Diabetes Risk Factors in Alaskan and Siberian Eskimos @ University of Alaska Anchorage
Support is requested for development of plans for a collaborative research project to determine prevalence of diabetes, hyperinsulinemia, cardiovascular risk factors, and certain genetic markers among Siberian Yupik Eskimos living on St. Lawrence Island in Alaska. The project would also investigate dietary patterns, physical activity levels, and anthropometric data and attempt to correlate these with the occurrence of diabetes, cardiovascular risk factors, diabetes complications, and insulin levels. As part of the ongoing Alaska-Siberia Medical Research Program, data will also be gathered in the population of Yupik Eskimos across the Bering Straits on the Chukotka Peninsula, USSR. Experience in Alaska has shown that screening projects provide a means to educate village residents about lifestyle risks for diabetes and to detect and treat cases of diabetes and other cardiovascular risk factors. Village leaders and health aides would be closely involved in the planning process as requested by Norton Sound Health Corporation. Age-adjusted prevalence of non-insulin dependent diabetes mellitus (NIDDM) among Alaska's Eskimos, Indians, and Aleuts overall increased 11%, from 15.7 to 17.4 per 1000 over the two-year period from 1985 to 1987 (Schraer et al., 1988). Rates in 1987 varied from 6.7 to 40.8 per 1000 in various Indian Health Service Units in Alaska. The estimated age-adjusted rate among Siberian Yupiks of St. Lawrence Island in 1989 was 9.2/1000 (7 cases, 1110 estimated population). These estimates are based only on clinically recognized cases. Comparing preliminary rates to Chukotka Natives 15 years old and older, we find that the St. Lawrence Island rate is 9.7/1000 while the Chukotka rate is 1/1000 (1989 data, Soviet rate based on screening studies). Since Siberian Yupik Eskimos of Chukotka and Alaska are genetically closely related, our working hypothesis is that dietary and lifestyle differences account for the difference in diabetes prevalence. We believe this represents a unique situation in that these populations were essentially united until 1949, when contact ceased due to political reasons, and lifestyles diverged as a result. Preliminary planning for this study began a year ago, but detailed plans remain to be formulated. We propose to bring together village leaders, the Norton Sound Health Board, scientists and clinicians in coordinated, identical surveys in Alaska and Siberia. Surveys among Native people of St Lawrence Island and the Chukotka region would include data similar to that being collected in the ongoing Strong Heart Study among other groups of Native Americans (Lee et al., 1990). Proposed planning activities will result in a grant proposal for a study likely to provide significant insights into the etiology of NIDDM and may lead to identification of causative lifestyle factors that can be modified to prevent diabetes.
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0.936 |
1993 — 1997 |
Ebbesson, Sven O |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Diabetes Prevention in Yupik Eskimos @ University of Alaska Fairbanks
Support is requested for a collaborative research project to determine to what extent intervention can decrease the prevalence of diabetes, hyperinsulinemia, and cardiovascular risk factors among Yupik Eskimos living on St. Lawrence Island and the west coast of Alaska. The project would also investigate dietary patterns, physical activity levels, and anthropometric data and attempt to correlate these with the occurrence of diabetes, cardiovascular risk factors, diabetes complications, and insulin levels. As part of the ongoing Alaska-Siberia Medical Research Program, identical baseline data are currently being gathered in the population of Yupik Eskimos across the Bering Straits on the Chukotka Peninsula in Siberia. Age-adjusted prevalence of non-insulin dependent diabetes mellitus (NIDDM) among Alaska's Eskimos, Indians, and Aleuts overall increased 11%, from 15.7 to 17.4 per 1000 over the two-year period form 1985 to 1987 (Schraer et al., 1988 and in press). Rates in 1987 varied from 6.7 to 40.8 per 1000 in various Indian Health Service units in Alaska. These estimates are based only on clinically recognized cases. Comparing preliminary rates to Chukotka Natives 15 years and older, we find that the SL Lawrence Island rate is 9.7/1000 while the Chukotka rate is 1/1000. Since Siberian Yupik Eskimos of Chukotka and Alaska are genetically closely related, our working hypothesis is that dietary and lifestyle differences account for the difference in diabetes prevalence. We believe this represents a unique opportunity for research since these populations were essentially one until 1948, when contact ceased due to political reasons, and lifestyles diverged as a result. Initially, a survey of 800 subjects of both sexes on St. Lawrence Island and western Alaska will be carried out using similar methodology as in the ongoing Strong Heart Study among other non-Alaskan groups of Native Americans. The surveys will be followed by an intervention in which half of the participating villages will receive specific education about diet and risk factors and will be encouraged to: a) eat more traditional foods, b) decrease foods with low nutrient density such as sugar in their diet, c) decrease intake of saturated fats, and d) increase physical exercise. Additional interventions will be implemented, based on recommendations and input from the community. The "control" villages will not receive these interventions. During the fifth year of this grant the effectiveness of the interventions will be tested by a careful comparison of diabetes and cardiovascular risk factors, repeating the same survey as given during year 1. Considering that the Alaskan Eskimos began abandoning traditional diets and lifestyles only recently, it is possible that the study might lead to a reversal in this trend by providing significant insights into the etiology of NIDDM and lead to identification of the causative lifestyle factors that can be modified to prevent diabetes.
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0.936 |