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• 61. [Article] Age progressive volcanism in the New England seamounts and the opening of the Central Atlantic Ocean

  copyrighted by American Geophysical Union

  Citation × Citation Citation Abstract Copy Title: Age progressive volcanism in the New England seamounts and the opening of the Central Atlantic Ocean Author: Duncan, Robert A. copyrighted by American Geophysical Union Title: Age progressive volcanism in the New England seamounts and the opening of the Central Atlantic Ocean Author: Duncan, Robert A. copyrighted by American Geophysical Union Close

• 62. [Article] Long-term patterns of diameter and basal area growth of old-growth Douglas-fir trees in western Oregon

  Diameter growth and age data collected from stumps of 505 recently cut old-growth Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) trees at 28 sample locations in western Oregon (U.S.A.) indicated that ...

  Citation × Citation Citation Abstract Copy Title: Long-term patterns of diameter and basal area growth of old-growth Douglas-fir trees in western Oregon Author: Poage, Nathan Jeremy, Tappeiner, John C., II Diameter growth and age data collected from stumps of 505 recently cut old-growth Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) trees at 28 sample locations in western Oregon (U.S.A.) indicated that rapid early and sustained growth of old Douglas-fir trees were extremely important in terms of attaining large diameters at ages 100–300 years. The diameters of the trees at ages 100–300 years (D100–D300) were strongly, positively, and linearly related to their diameters and basal area growth rates at age 50 years. Average periodic basal area increments (PAIBA) of all trees increased for the first 30–40 years and then plateaued, remaining relatively high and constant from age 50 to 300 years. Average PAIBA of the largest trees at ages 100–300 years were significantly greater by age 20 years than were those of smaller trees at ages 100–300 years. The site factors province, site class, slope, aspect, elevation, and establishment year accounted for little of the variation observed in basal area growth at age 50 years and D100–D300. The mean age range for old-growth Douglas-fir at the sample locations was wide (174 years). The hypothesis that large-diameter old-growth Douglas-fir developed at low stand densities was supported by these observations. Title: Long-term patterns of diameter and basal area growth of old-growth Douglas-fir trees in western Oregon Author: Poage, Nathan Jeremy, Tappeiner, John C., II Diameter growth and age data collected from stumps of 505 recently cut old-growth Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) trees at 28 sample locations in western Oregon (U.S.A.) indicated that rapid early and sustained growth of old Douglas-fir trees were extremely important in terms of attaining large diameters at ages 100–300 years. The diameters of the trees at ages 100–300 years (D100–D300) were strongly, positively, and linearly related to their diameters and basal area growth rates at age 50 years. Average periodic basal area increments (PAIBA) of all trees increased for the first 30–40 years and then plateaued, remaining relatively high and constant from age 50 to 300 years. Average PAIBA of the largest trees at ages 100–300 years were significantly greater by age 20 years than were those of smaller trees at ages 100–300 years. The site factors province, site class, slope, aspect, elevation, and establishment year accounted for little of the variation observed in basal area growth at age 50 years and D100–D300. The mean age range for old-growth Douglas-fir at the sample locations was wide (174 years). The hypothesis that large-diameter old-growth Douglas-fir developed at low stand densities was supported by these observations. Close

• 63. [Article] Wood density of young-growth western hemlock: relation to ring age, radial growth, stand density, and site quality

  Breast-high stem sections were sampled from 56 western hemlock (Tsuga heterophylla (Raf.) Sarg.) trees growing in 15 plots representing a wide range of tree and site conditions in northwestern Oregon. ...

  Citation × Citation Citation Abstract Copy Title: Wood density of young-growth western hemlock: relation to ring age, radial growth, stand density, and site quality Author: Marshall, D. D., Gartner, B. L., Singleton, R., DeBell, D. S. Breast-high stem sections were sampled from 56 western hemlock (Tsuga heterophylla (Raf.) Sarg.) trees growing in 15 plots representing a wide range of tree and site conditions in northwestern Oregon. Growth and wood density traits of individual rings were measured via X-ray densitometry, and relationships of ring density and its components to age and growth rate were analyzed. Ring density was highest (0.49 g/cm3) near the pith, declined to 0.40 g/cm3 at age 10, remained stable to about age 25, and then increased gradually and remained between 0.43 and 0.44 g/cm3 from age 38 to 45 and beyond. A negative influence of rapid growth on whole ring density was greatest at young ages and diminished with time, becoming nonsignificant beyond age 30. Earlywood density, latewood density, and latewood proportion were all negatively related to ring width at young ages, but by age 21–25, latewood proportion was the only component of ring density that remained significantly diminished by increased growth rate. Residual differences in wood density (after age and growth rate were considered) did not appear to be related to either stand density or site class. Overall, young-growth hemlock trees are relatively uniform in wood density and likely to be more so if grown in intensively managed stands. Title: Wood density of young-growth western hemlock: relation to ring age, radial growth, stand density, and site quality Author: Marshall, D. D., Gartner, B. L., Singleton, R., DeBell, D. S. Breast-high stem sections were sampled from 56 western hemlock (Tsuga heterophylla (Raf.) Sarg.) trees growing in 15 plots representing a wide range of tree and site conditions in northwestern Oregon. Growth and wood density traits of individual rings were measured via X-ray densitometry, and relationships of ring density and its components to age and growth rate were analyzed. Ring density was highest (0.49 g/cm3) near the pith, declined to 0.40 g/cm3 at age 10, remained stable to about age 25, and then increased gradually and remained between 0.43 and 0.44 g/cm3 from age 38 to 45 and beyond. A negative influence of rapid growth on whole ring density was greatest at young ages and diminished with time, becoming nonsignificant beyond age 30. Earlywood density, latewood density, and latewood proportion were all negatively related to ring width at young ages, but by age 21–25, latewood proportion was the only component of ring density that remained significantly diminished by increased growth rate. Residual differences in wood density (after age and growth rate were considered) did not appear to be related to either stand density or site class. Overall, young-growth hemlock trees are relatively uniform in wood density and likely to be more so if grown in intensively managed stands. Close

• 64. [Article] A comparison of body composition, body cathexis, and attitude toward obesity in women with different levels of physical activity

  The purpose of this study was to identify significant differences in body composition, body cathexis, and attitudes toward obesity of women in various age groups involved in different levels of physical exercise. A ...

  Citation × Citation Citation Abstract Copy Title: A comparison of body composition, body cathexis, and attitude toward obesity in women with different levels of physical activity Author: Lai, Shu-mei The purpose of this study was to identify significant differences in body composition, body cathexis, and attitudes toward obesity of women in various age groups involved in different levels of physical exercise. A total of 216 women, ranging in age from 17 to 64, took part in this study. They were classified into three age groups: col legeage, beyond college-age, and middle-aged, then further divided into three exercise categories: very active, moderately active, and relatively inactive. All subjects completed the Physical Activity and Body Cathexis Survey. Then the subjects submitted themselves to a series of skinfold fat measurement. In determining the subjects' feelings toward their bodies, the Secord and Jourard's Body Cathexis Scale (1953) was utilized to collect the data. Bray's Obesity Attitude Scale (1973) was employed to investigate the subjects' attitudes toward obesity. The prediction equation developed by Jackson et al. (1980) was used to determine the subjects' body density. The measurements were taken at triceps,thigh, and suprailium skinfolds. The percentage of body fat was derived from the formula of Siri's (1961). The results indicated that the middle-aged women had a higher percentage of body fat and lower amount of lean body mass than the beyond college-age women. There was, however, no significant difference between the body composition of the col lege-age and the beyond college-age women. Different levels of physical activity performed by women had significant effects on their body fat percentage and their body cathexis. Subjects in the very active level of physical exercise showed the lowest percentage of body fat and the most positive attitudes toward their bodies. Attitudes toward obesity between women, young or old, exercising or not exercising, were not significantly different. Women's obesity attitudes were not affected by either age or levels of physical activity. Title: A comparison of body composition, body cathexis, and attitude toward obesity in women with different levels of physical activity Author: Lai, Shu-mei The purpose of this study was to identify significant differences in body composition, body cathexis, and attitudes toward obesity of women in various age groups involved in different levels of physical exercise. A total of 216 women, ranging in age from 17 to 64, took part in this study. They were classified into three age groups: col legeage, beyond college-age, and middle-aged, then further divided into three exercise categories: very active, moderately active, and relatively inactive. All subjects completed the Physical Activity and Body Cathexis Survey. Then the subjects submitted themselves to a series of skinfold fat measurement. In determining the subjects' feelings toward their bodies, the Secord and Jourard's Body Cathexis Scale (1953) was utilized to collect the data. Bray's Obesity Attitude Scale (1973) was employed to investigate the subjects' attitudes toward obesity. The prediction equation developed by Jackson et al. (1980) was used to determine the subjects' body density. The measurements were taken at triceps,thigh, and suprailium skinfolds. The percentage of body fat was derived from the formula of Siri's (1961). The results indicated that the middle-aged women had a higher percentage of body fat and lower amount of lean body mass than the beyond college-age women. There was, however, no significant difference between the body composition of the col lege-age and the beyond college-age women. Different levels of physical activity performed by women had significant effects on their body fat percentage and their body cathexis. Subjects in the very active level of physical exercise showed the lowest percentage of body fat and the most positive attitudes toward their bodies. Attitudes toward obesity between women, young or old, exercising or not exercising, were not significantly different. Women's obesity attitudes were not affected by either age or levels of physical activity. Close

• 65. [Article] Sensitivity of the stock synthesis assessment model : a simulation approach

  Stock assessments for many U.S. Pacific coast groundfish stocks are developed using the catch-at-age method known as Stock Synthesis. In this work a simulation package was developed and used to evaluate ...

  Citation × Citation Citation Abstract Copy Title: Sensitivity of the stock synthesis assessment model : a simulation approach Author: Yin, Yanshui Stock assessments for many U.S. Pacific coast groundfish stocks are developed using the catch-at-age method known as Stock Synthesis. In this work a simulation package was developed and used to evaluate the sensitivity of the Stock Synthesis program. More specifically, the evaluation focused on the impacts of input data errors and stock characteristics on the accuracy and precision of Synthesis estimates. Factors examined included the length of the time series of data, the rate of natural mortality, the shape of the fishery and survey selectivity curves, the trend in the rate of fishing mortality, the recruitment pattern, and errors in the observed data for annual catch, fishing effort, fishery and survey age composition, and survey biomass indices. First, the study evaluated the sensitivity of the Stock Synthesis program applied to populations with simple multinomial age compositions. The length of the data series and sample size were the two most influential factors. Second, the study focused on populations with compound multinomial age composition, in which the age composition data were over-dispersed relative to simple multinomial samples. When the fishery age composition actually followed a compound multinomial distribution, the estimates produced by the Stock Synthesis program, which assumed simple multinomial distributions with maximum sample sizes of 400 fish, were moderately more biased and more variable. When applying Synthesis to populations whose age compositions follow compound multinomial distributions, the results from the experiments indicated that a common configuration, in which age sample sizes in the likelihood specification are limited to 400 fish per sample, probably gives age composition data too much emphasis. The experiments indicated that using 200 as the upper limit provided more accurate results than using 400. Third, the actual stock assessment of yellowfin sole (Limanda Aspera) was taken as a case study and it was found that more accurate assessment results could be achieved from a better balance in the amount of sampling effort allocated to age composition data versus survey biomass estimates. Title: Sensitivity of the stock synthesis assessment model : a simulation approach Author: Yin, Yanshui Stock assessments for many U.S. Pacific coast groundfish stocks are developed using the catch-at-age method known as Stock Synthesis. In this work a simulation package was developed and used to evaluate the sensitivity of the Stock Synthesis program. More specifically, the evaluation focused on the impacts of input data errors and stock characteristics on the accuracy and precision of Synthesis estimates. Factors examined included the length of the time series of data, the rate of natural mortality, the shape of the fishery and survey selectivity curves, the trend in the rate of fishing mortality, the recruitment pattern, and errors in the observed data for annual catch, fishing effort, fishery and survey age composition, and survey biomass indices. First, the study evaluated the sensitivity of the Stock Synthesis program applied to populations with simple multinomial age compositions. The length of the data series and sample size were the two most influential factors. Second, the study focused on populations with compound multinomial age composition, in which the age composition data were over-dispersed relative to simple multinomial samples. When the fishery age composition actually followed a compound multinomial distribution, the estimates produced by the Stock Synthesis program, which assumed simple multinomial distributions with maximum sample sizes of 400 fish, were moderately more biased and more variable. When applying Synthesis to populations whose age compositions follow compound multinomial distributions, the results from the experiments indicated that a common configuration, in which age sample sizes in the likelihood specification are limited to 400 fish per sample, probably gives age composition data too much emphasis. The experiments indicated that using 200 as the upper limit provided more accurate results than using 400. Third, the actual stock assessment of yellowfin sole (Limanda Aspera) was taken as a case study and it was found that more accurate assessment results could be achieved from a better balance in the amount of sampling effort allocated to age composition data versus survey biomass estimates. Close

• 66. [Article] The vertically-oriented organization : a theoretical perspective

  This study will focus on a particular program (The Area Agency on Aging) which was developed in response to the problems of fragmentation among the service delivery system for the aging. In so doing, two ...

  Citation × Citation Citation Abstract Copy Title: The vertically-oriented organization : a theoretical perspective Author: Kurren, Beth M. Year: 1977 This study will focus on a particular program (The Area Agency on Aging) which was developed in response to the problems of fragmentation among the service delivery system for the aging. In so doing, two very important questions will be answered: 1. To what extent do the characteristics of the Area Agency on Aging resemble a vertically-oriented organization? 2. To what extent does the Area Agency on Aging gear its activities toward the coordination of services for the elderly? The basic assumption is that because the Area Agency on Aging resembles another vertically- oriented organization, its main focus of attention will be on internal concerns (i.e., survival) rather than inter-organizational activities. Title: The vertically-oriented organization : a theoretical perspective Author: Kurren, Beth M. Year: 1977 This study will focus on a particular program (The Area Agency on Aging) which was developed in response to the problems of fragmentation among the service delivery system for the aging. In so doing, two very important questions will be answered: 1. To what extent do the characteristics of the Area Agency on Aging resemble a vertically-oriented organization? 2. To what extent does the Area Agency on Aging gear its activities toward the coordination of services for the elderly? The basic assumption is that because the Area Agency on Aging resembles another vertically- oriented organization, its main focus of attention will be on internal concerns (i.e., survival) rather than inter-organizational activities. Close

• 67. [Article] The Influence of Age and Stimuli on the Explanations of "Same" and "Different" by Young Children

  This study investigated the influence of chronological age and stimuli on the explanations of "same" and "different" by young children. Seventy children, between by young children. the ages of three-years, ...

  Citation × Citation Citation Abstract Copy Title: The Influence of Age and Stimuli on the Explanations of "Same" and "Different" by Young Children Author: Senders, Pamela Callas Year: 1977 This study investigated the influence of chronological age and stimuli on the explanations of "same" and "different" by young children. Seventy children, between by young children. the ages of three-years, six-months and nine-years, six-months, selected on the basis of chronological age, normal speech and language development, and normal verbal maturity, were involved as subjects. A test consisting of a series of verbal tasks was administered to each child. The experimenter recorded and later analyzed and classified all responses for each child, following specific guidelines for judging appropriateness of response and assigning each appropriate response to one of three classifications. Title: The Influence of Age and Stimuli on the Explanations of "Same" and "Different" by Young Children Author: Senders, Pamela Callas Year: 1977 This study investigated the influence of chronological age and stimuli on the explanations of "same" and "different" by young children. Seventy children, between by young children. the ages of three-years, six-months and nine-years, six-months, selected on the basis of chronological age, normal speech and language development, and normal verbal maturity, were involved as subjects. A test consisting of a series of verbal tasks was administered to each child. The experimenter recorded and later analyzed and classified all responses for each child, following specific guidelines for judging appropriateness of response and assigning each appropriate response to one of three classifications. Close

• 68. [Article] Negative behavior exhibited by preschool children in same-age versus mixed-age groups

  Perhaps due to the increase in the workforce of mothers with young children, much attention has been directed in the past decade towards the subject of out-of-home child care. In order to gain further ...

  Citation × Citation Citation Abstract Copy Title: Negative behavior exhibited by preschool children in same-age versus mixed-age groups Author: Sheppard, Laura Janine Year: 1985 Perhaps due to the increase in the workforce of mothers with young children, much attention has been directed in the past decade towards the subject of out-of-home child care. In order to gain further understanding of the socialization of preschool children, an observational study was carried out which was designed to measure the amount of negative behavior expressed by children participating in mixed-age versus same-age preschool groups. Title: Negative behavior exhibited by preschool children in same-age versus mixed-age groups Author: Sheppard, Laura Janine Year: 1985 Perhaps due to the increase in the workforce of mothers with young children, much attention has been directed in the past decade towards the subject of out-of-home child care. In order to gain further understanding of the socialization of preschool children, an observational study was carried out which was designed to measure the amount of negative behavior expressed by children participating in mixed-age versus same-age preschool groups. Close

• 69. [Article] Optimal harvesting of continuous age structured populations

  We investigate the optimal harvesting strategies for McKendrick type population models. Models of this type endow the population with a continuous age structure. They consist of a partial differential ...

  Citation × Citation Citation Abstract Copy Title: Optimal harvesting of continuous age structured populations Author: Smith, Steven J. We investigate the optimal harvesting strategies for McKendrick type population models. Models of this type endow the population with a continuous age structure. They consist of a partial differential equation with a boundary condition which involves an integral of the solution. We study two problems, the first concerns the yield on an infinite time interval of a linear model. It is shown that an optimal policy exists, and that it consists of harvesting at no more than three specific ages. The optimal harvesting ages are dependent on the birth and death rates, and the economic parameters of the problem. The goal of the second problem is to find the harvesting policy that maximizes the sustainable yield of a nonlinear model. It is shown that a maximal sustainable yield exists, and is accomplished by harvesting at only two ages. Title: Optimal harvesting of continuous age structured populations Author: Smith, Steven J. We investigate the optimal harvesting strategies for McKendrick type population models. Models of this type endow the population with a continuous age structure. They consist of a partial differential equation with a boundary condition which involves an integral of the solution. We study two problems, the first concerns the yield on an infinite time interval of a linear model. It is shown that an optimal policy exists, and that it consists of harvesting at no more than three specific ages. The optimal harvesting ages are dependent on the birth and death rates, and the economic parameters of the problem. The goal of the second problem is to find the harvesting policy that maximizes the sustainable yield of a nonlinear model. It is shown that a maximal sustainable yield exists, and is accomplished by harvesting at only two ages. Close

• 70. [Article] Mechanisms that influence the posttranslational modification of the GluN2B subunit in the aged brain

  Memory is essential to everyday life. As we age, deficits in memory become apparent. The toll of age-related cognitive impairment can be devastating to families and costly to society. The NMDA receptor ...

  Citation × Citation Citation Abstract Copy Title: Mechanisms that influence the posttranslational modification of the GluN2B subunit in the aged brain Author: Zamzow, Daniel R. Memory is essential to everyday life. As we age, deficits in memory become apparent. The toll of age-related cognitive impairment can be devastating to families and costly to society. The NMDA receptor is a molecule in the brain that is instrumental in the formation of memories. The receptor is particularly vulnerable to the effects of aging. Of the fourteen known subunits, the GluN2B subunit has the greatest effect on memory. The subunit also suffers from the greatest loss of expression due to aging. The present study examines the interactions of GluN2B with other proteins and quantifies the changes in posttranslational modification with age. Co-immunoprecipitation was used to measure the interaction of GluN2B with the scaffolding molecules PSD-95 and GIPC in synaptosomes from the frontal cortex of behaviorally characterized mice of three ages. The interaction between GluN2A and GluN2B was also measured. There were more PSD-95 and GluN2A molecules per GluN2B with age. The increased PSD-95/GluN2B relationship in old mice was associated with poorer memory. The GIPC/GluN2B relationship also correlated with spatial reference memory. The GluN2B/GluN2A relationship indicated an increase in triheteromeric receptors in the aged mouse, but it did not correlate with memory declines during aging. These results suggest that an age-related increase in PSD-95/GluN2B is detrimental to memory. Young and old mice were behaviorally characterized and homogenates from the frontal cortex and hippocampus were separated by differential centrifugation followed by lysis in Triton X-100. Western blots containing proteins from each cellular fraction were probed with antibodies for several proteins in the NMDA receptor complex. There was an age-related increase in p1472 in the synaptic fraction from the frontal cortex and an increase in the 115 kDa calpain-mediated cleavage product of GluN2B in the extrasynaptic fraction of old mice with good reference memory. Fyn was increased and p1336 was decreased in the synaptic membranes of poor learners. The percentage of GluN2B, GluN2A, Fyn, and PSD-95 molecules that were palmitoylated increased in an age-dependent manner in the frontal cortex, but not the hippocampus. The thioesterase, APT1, also had an age-related increase in palmitoylation in the frontal cortex. These results suggest that the palmitoylation cycle may be perturbed in the frontal cortex of aged brains and this may influence further processing of the GluN2B subunit. In the last study we attempted to lower levels of protein palmitoylation in aged mice by lowering systemic levels of palmitate. Xanthohumol is a flavonoid from hops that increases beta-oxidation in the liver thereby decreasing systemic levels of fatty acids. Mice were fed a diet supplemented with xanthohumol and behaviorally characterized in the Morris water maze. There was a small treatment effect on cognitive flexibility in the young mice, but this appeared to be a recovery from the negative effects of a phytoestrogen-deficient diet. Treatment with xanthohumol significantly lowered levels of palmitate in the plasma of old mice, but palmitoyl-CoA and protein palmitoylation was unaffected. These results suggest that there may be some promise in using xanthohumol for the treatment of metabolic syndrome, but it may not be suitable for lowering levels of protein palmitoylation in the brain. These results presented in this thesis suggest that an age-related increase in palmitoylation of GluN2B and NMDA receptor effector proteins in the brain may affect the function of neurons in the frontal cortex in two ways. First, increased p1472 enhances clustering of GluN2B-containing NMDA receptors on the synaptic membrane, thereby preserving memory in some old mice. Second, an age-related increase in the calpain-mediated cleavage of GluN2B may eventually lead to increased cell death. Interventions that reduce systemic levels of palmitate may not be effective in treating memory deficits. What is needed is a greater understanding of the mechanisms that govern the palmitoylation cycle in brain in order to design more targeted interventions in the future. Title: Mechanisms that influence the posttranslational modification of the GluN2B subunit in the aged brain Author: Zamzow, Daniel R. Memory is essential to everyday life. As we age, deficits in memory become apparent. The toll of age-related cognitive impairment can be devastating to families and costly to society. The NMDA receptor is a molecule in the brain that is instrumental in the formation of memories. The receptor is particularly vulnerable to the effects of aging. Of the fourteen known subunits, the GluN2B subunit has the greatest effect on memory. The subunit also suffers from the greatest loss of expression due to aging. The present study examines the interactions of GluN2B with other proteins and quantifies the changes in posttranslational modification with age. Co-immunoprecipitation was used to measure the interaction of GluN2B with the scaffolding molecules PSD-95 and GIPC in synaptosomes from the frontal cortex of behaviorally characterized mice of three ages. The interaction between GluN2A and GluN2B was also measured. There were more PSD-95 and GluN2A molecules per GluN2B with age. The increased PSD-95/GluN2B relationship in old mice was associated with poorer memory. The GIPC/GluN2B relationship also correlated with spatial reference memory. The GluN2B/GluN2A relationship indicated an increase in triheteromeric receptors in the aged mouse, but it did not correlate with memory declines during aging. These results suggest that an age-related increase in PSD-95/GluN2B is detrimental to memory. Young and old mice were behaviorally characterized and homogenates from the frontal cortex and hippocampus were separated by differential centrifugation followed by lysis in Triton X-100. Western blots containing proteins from each cellular fraction were probed with antibodies for several proteins in the NMDA receptor complex. There was an age-related increase in p1472 in the synaptic fraction from the frontal cortex and an increase in the 115 kDa calpain-mediated cleavage product of GluN2B in the extrasynaptic fraction of old mice with good reference memory. Fyn was increased and p1336 was decreased in the synaptic membranes of poor learners. The percentage of GluN2B, GluN2A, Fyn, and PSD-95 molecules that were palmitoylated increased in an age-dependent manner in the frontal cortex, but not the hippocampus. The thioesterase, APT1, also had an age-related increase in palmitoylation in the frontal cortex. These results suggest that the palmitoylation cycle may be perturbed in the frontal cortex of aged brains and this may influence further processing of the GluN2B subunit. In the last study we attempted to lower levels of protein palmitoylation in aged mice by lowering systemic levels of palmitate. Xanthohumol is a flavonoid from hops that increases beta-oxidation in the liver thereby decreasing systemic levels of fatty acids. Mice were fed a diet supplemented with xanthohumol and behaviorally characterized in the Morris water maze. There was a small treatment effect on cognitive flexibility in the young mice, but this appeared to be a recovery from the negative effects of a phytoestrogen-deficient diet. Treatment with xanthohumol significantly lowered levels of palmitate in the plasma of old mice, but palmitoyl-CoA and protein palmitoylation was unaffected. These results suggest that there may be some promise in using xanthohumol for the treatment of metabolic syndrome, but it may not be suitable for lowering levels of protein palmitoylation in the brain. These results presented in this thesis suggest that an age-related increase in palmitoylation of GluN2B and NMDA receptor effector proteins in the brain may affect the function of neurons in the frontal cortex in two ways. First, increased p1472 enhances clustering of GluN2B-containing NMDA receptors on the synaptic membrane, thereby preserving memory in some old mice. Second, an age-related increase in the calpain-mediated cleavage of GluN2B may eventually lead to increased cell death. Interventions that reduce systemic levels of palmitate may not be effective in treating memory deficits. What is needed is a greater understanding of the mechanisms that govern the palmitoylation cycle in brain in order to design more targeted interventions in the future. Close