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• 61. [Article] Interactive video communication technology and successful aging in place : applying the selective optimization with compensation model

  This study utilized the theoretical framework of selective optimization with compensation (SOC) (Baltes, 1987; Baltes & Baltes, 1990) to interpret older adults' definitions about successful aging in place. ...

  Citation × Citation Citation Abstract Copy Title: Interactive video communication technology and successful aging in place : applying the selective optimization with compensation model Author: Yamamoto, Toshiko This study utilized the theoretical framework of selective optimization with compensation (SOC) (Baltes, 1987; Baltes & Baltes, 1990) to interpret older adults' definitions about successful aging in place. Factors contributing to successful aging in place, including the importance of social interaction and perceptions of the usefulness of interactive video communication technology (IVC) for achieving optimal levels of social interaction and successful aging in place, were also determined. Data were collected using a questionnaire, home-observation checklist, seven-day social interaction diary, and in-depth interviews. The sample consisted of 14 women and four men who were over 75 years of age and living in their own homes. The participants were predominantly white, educated, mobile, and in good health. All participants declared that they would like to continue living in their own homes as long as possible. More than two-thirds had lived for over 30 years in their homes. Three major themes emerged from this study: successful aging in place, social interaction, and usefulness of IVC for aging in place. Participants' definitions of successful aging in place included factors related to health, mobility, independence, control, solitude, affordability, comfort, and social interactions. Social interactions represented, in the respondents' opinions, a major factor for successful aging in place. The participants had an active social life, employing a variety of social communication means, from face-to-face interactions and telephone to computers. Their social activities included club memberships, church activities, informal interactions with family members and friends, and formal interactions, especially with health care providers. The participants in this study did not perceive the IVC technology as important for their aging in place in their current situations. However, the participants admitted that the IVC could be a useful tool for people with limited health and mobility to allow them to maintain social interactions and successfully age in place. The interpretation of the findings is as follows: at their actual level of activity and mobility, the participants selected particular ways of communication and optimized these means. The IVC was perceived as a compensation mechanism to be used when other communication means fail due to health and mobility problems. Title: Interactive video communication technology and successful aging in place : applying the selective optimization with compensation model Author: Yamamoto, Toshiko This study utilized the theoretical framework of selective optimization with compensation (SOC) (Baltes, 1987; Baltes & Baltes, 1990) to interpret older adults' definitions about successful aging in place. Factors contributing to successful aging in place, including the importance of social interaction and perceptions of the usefulness of interactive video communication technology (IVC) for achieving optimal levels of social interaction and successful aging in place, were also determined. Data were collected using a questionnaire, home-observation checklist, seven-day social interaction diary, and in-depth interviews. The sample consisted of 14 women and four men who were over 75 years of age and living in their own homes. The participants were predominantly white, educated, mobile, and in good health. All participants declared that they would like to continue living in their own homes as long as possible. More than two-thirds had lived for over 30 years in their homes. Three major themes emerged from this study: successful aging in place, social interaction, and usefulness of IVC for aging in place. Participants' definitions of successful aging in place included factors related to health, mobility, independence, control, solitude, affordability, comfort, and social interactions. Social interactions represented, in the respondents' opinions, a major factor for successful aging in place. The participants had an active social life, employing a variety of social communication means, from face-to-face interactions and telephone to computers. Their social activities included club memberships, church activities, informal interactions with family members and friends, and formal interactions, especially with health care providers. The participants in this study did not perceive the IVC technology as important for their aging in place in their current situations. However, the participants admitted that the IVC could be a useful tool for people with limited health and mobility to allow them to maintain social interactions and successfully age in place. The interpretation of the findings is as follows: at their actual level of activity and mobility, the participants selected particular ways of communication and optimized these means. The IVC was perceived as a compensation mechanism to be used when other communication means fail due to health and mobility problems. Close

• 62. [Article] Endocrinology of sex-linked-recessive dwarf White Leghorn chickens, Gallus Domesticus, with special reference to the thyroid

  A comparison of the various endocrine glands, in addition to other anatomical measurements, was made on 19 normal and 21 dwarf 2-3-month-old females and 20 normal and 20 dwarf 7-13-month-old females of ...

  Citation × Citation Citation Abstract Copy Title: Endocrinology of sex-linked-recessive dwarf White Leghorn chickens, Gallus Domesticus, with special reference to the thyroid Author: Mirosh, Larry Wayne A comparison of the various endocrine glands, in addition to other anatomical measurements, was made on 19 normal and 21 dwarf 2-3-month-old females and 20 normal and 20 dwarf 7-13-month-old females of the White Leghorn breed. At both ages, dwarfs weighed significantly less and had significantly shorter shanks than normals. Comb weight and comb area (L X H) were significantly larger in normals than in dwarfs 7-13 months of age, but no significant difference was found in the 2-3 month age group. Ovaries in the 2-3 month age group were heavier in normals than in dwarfs, due to greater gonadotropin secretion in relation to body size. The divergent results in weight of the hypophyses on an absolute and a relative-to-body-weight basis may be attributed to the algebraic sum of synthesis storage and liberation of hormones by this gland. Also, absolute and relative weights of the adrenals did not always coincide in both age groups, which may be attributed to environmental factors influencing the release of ACTH from the hypophysis. The normals had significantly heavier thyroids than dwarfs. on an absolute and on a relative weight basis at both ages, which does not necessarily indicate a hyper- or hypothyroid condition in the latter group of birds. Normals secreted significantly more thyroxine than dwarfs at 7-13 months of age; whereas, no significant difference was found between these two types of chickens at 2-3 months of age, as determined by epithelial cell height. The significantly smaller colloid and follicle diameter found in thyroids of dwarfs than of normals may be attributed to the lower gland weights in the former group. Bioassay of the hypophyses from these chickens was conducted in immature, hypophysectomized, female rats. Dwarfs did not differ significantly from normals in STH activity, according to the tibia test, body weight gain and tail length. Greater epiphyseal plate responses were obtained from hypophyses of growing chickens. Thymus weight varied with dosage, which is attributed to several hormones acting on this gland. The normals had a significantly higher hypophyseal ACTH content than dwarfs 2-3 months of age, which is believed to be due to the hormone content of the hypophyses at the time of removal, rather than to dwarfism. Also, the younger birds were observed to have a higher ACTH content than older birds, which may be due to storage of this hormone in the hypophysis during the growing period. Dwarfs did not differ significantly from normals in gonadotropic activity at both ages, as evaluated by ovary, oviduct and uterus weight response in the assay rats. However, the older birds were observed to have higher gonadotropic activity than younger birds, as determined by ovary, oviduct and uterine weight and vaginal openings in the rats. No significant difference in FSH content of the hypophyses of dwarfs and normals of both ages was found, using ovarian follicle diameter. Observation of the interstitial cells in the rat ovaries revealed no difference between dwarfs and normals at both age classifications in ICSH content. No significant difference in TSH activity between dwarfs and normals within each age group was found, based on thyroid weight in the rats. Also, dwarfs did not appear to differ from normals of both ages in measurements on epithelial cell height and colloid and follicle diameter. Lack of appreciable differences between the treated rats and the controls in these measurements on the thyroids would indicate that rats did not respond to avian TSH. Title: Endocrinology of sex-linked-recessive dwarf White Leghorn chickens, Gallus Domesticus, with special reference to the thyroid Author: Mirosh, Larry Wayne A comparison of the various endocrine glands, in addition to other anatomical measurements, was made on 19 normal and 21 dwarf 2-3-month-old females and 20 normal and 20 dwarf 7-13-month-old females of the White Leghorn breed. At both ages, dwarfs weighed significantly less and had significantly shorter shanks than normals. Comb weight and comb area (L X H) were significantly larger in normals than in dwarfs 7-13 months of age, but no significant difference was found in the 2-3 month age group. Ovaries in the 2-3 month age group were heavier in normals than in dwarfs, due to greater gonadotropin secretion in relation to body size. The divergent results in weight of the hypophyses on an absolute and a relative-to-body-weight basis may be attributed to the algebraic sum of synthesis storage and liberation of hormones by this gland. Also, absolute and relative weights of the adrenals did not always coincide in both age groups, which may be attributed to environmental factors influencing the release of ACTH from the hypophysis. The normals had significantly heavier thyroids than dwarfs. on an absolute and on a relative weight basis at both ages, which does not necessarily indicate a hyper- or hypothyroid condition in the latter group of birds. Normals secreted significantly more thyroxine than dwarfs at 7-13 months of age; whereas, no significant difference was found between these two types of chickens at 2-3 months of age, as determined by epithelial cell height. The significantly smaller colloid and follicle diameter found in thyroids of dwarfs than of normals may be attributed to the lower gland weights in the former group. Bioassay of the hypophyses from these chickens was conducted in immature, hypophysectomized, female rats. Dwarfs did not differ significantly from normals in STH activity, according to the tibia test, body weight gain and tail length. Greater epiphyseal plate responses were obtained from hypophyses of growing chickens. Thymus weight varied with dosage, which is attributed to several hormones acting on this gland. The normals had a significantly higher hypophyseal ACTH content than dwarfs 2-3 months of age, which is believed to be due to the hormone content of the hypophyses at the time of removal, rather than to dwarfism. Also, the younger birds were observed to have a higher ACTH content than older birds, which may be due to storage of this hormone in the hypophysis during the growing period. Dwarfs did not differ significantly from normals in gonadotropic activity at both ages, as evaluated by ovary, oviduct and uterus weight response in the assay rats. However, the older birds were observed to have higher gonadotropic activity than younger birds, as determined by ovary, oviduct and uterine weight and vaginal openings in the rats. No significant difference in FSH content of the hypophyses of dwarfs and normals of both ages was found, using ovarian follicle diameter. Observation of the interstitial cells in the rat ovaries revealed no difference between dwarfs and normals at both age classifications in ICSH content. No significant difference in TSH activity between dwarfs and normals within each age group was found, based on thyroid weight in the rats. Also, dwarfs did not appear to differ from normals of both ages in measurements on epithelial cell height and colloid and follicle diameter. Lack of appreciable differences between the treated rats and the controls in these measurements on the thyroids would indicate that rats did not respond to avian TSH. Close

• 63. [Article] The use of time by homemakers with children

  The purpose of the study was to find out how a group of faculty wives with children used their time and to investigate some factors in housing and equipment which might influence how they used their time. ...

  Citation × Citation Citation Abstract Copy Title: The use of time by homemakers with children Author: Meyer, Bonnie Martin The purpose of the study was to find out how a group of faculty wives with children used their time and to investigate some factors in housing and equipment which might influence how they used their time. A comparison was made between homemakers with two pre-school age children and homemakers with two school age children in the way they used their time. Following a letter of explanation of the study, the writer contacted the homemakers by phone to make an appointment to visit them. During this visit the writer obtained the information for the questionnaire and explained the time sheets. Twenty-four homemakers, 12 with pre-school children, and 12 with school-age children kept usable records for this study. The homemakers ranged in age from 21 to 62 years of age. All of the homemakers had attended college with 42 percent graduating and an additional 16.5 percent earning their master's degree. Two were registered nurses. Both groups averaged four years of work before marriage. The homemakers with pre-school children had been married an average of eight years while the homemakers with school age children had been married an average of 18 years. The children ranged in age from four months to 18 years old. The 12.5 percent of the families that did not own their own homes were all from the group with pre-school children. Although all of the homes were well equipped, the families that had been established the longest time had slightly more equipment. Half of the total group used time plans; the majority of the homemakers using time plans were homemakers with pre-school children. Homemakers in this study as well as previous studies most often listed food preparation as the homemaking activity they most enjoyed. Again, cleaning house was most often listed as the activity least enjoyed, followed by ironing. Improved housing, equipment, and methods have failed to change these attitudes in over a quarter of a century. The homemakers with pre-school children spent the greatest percentage of their time caring for children followed by meal preparation and clean-up; the homemakers with school age children spent the greatest percentage of their time on food preparation and clean-up. Both groups spent a little over two and a half hours on meal preparation and clean-up. Homemakers with school age children averaged 48 minutes a day on laundry, whereas homemakers with pre-school children averaged 70 minutes a day. Cleaning house averaged 63 minutes a day for homemakers with school age children and 45 minutes a day for homemakers with pre-school children. Homemakers with school age children averaged 39 minutes for shopping, whereas homemakers with pre-school children averaged 23 minutes. The homemakers with school age children averaged 8 hours and 45 minutes of rest per day, whereas the homemakers with pre-school children averaged 8 hours and 8 minutes. Homemakers with school age children spent more time eating meals, on personal care, and on entertaining and social activities, whereas homemakers with pre-school children derived much of their leisure time from unplanned coffee breaks and chatting with neighbors. Other than the great difference in the amount of time the two groups spent in caring for their children, (the homemakers with pre-school children spent 3 hours and 38 minutes while the homemakers with school age children spent 39 minutes), there was great similarity in the way the two groups used their time. Another finding is that there is little difference in the amount of time the homemaker spent on different homemaking activities at the time of this study in comparison to studies done during the past quarter of a century. Title: The use of time by homemakers with children Author: Meyer, Bonnie Martin The purpose of the study was to find out how a group of faculty wives with children used their time and to investigate some factors in housing and equipment which might influence how they used their time. A comparison was made between homemakers with two pre-school age children and homemakers with two school age children in the way they used their time. Following a letter of explanation of the study, the writer contacted the homemakers by phone to make an appointment to visit them. During this visit the writer obtained the information for the questionnaire and explained the time sheets. Twenty-four homemakers, 12 with pre-school children, and 12 with school-age children kept usable records for this study. The homemakers ranged in age from 21 to 62 years of age. All of the homemakers had attended college with 42 percent graduating and an additional 16.5 percent earning their master's degree. Two were registered nurses. Both groups averaged four years of work before marriage. The homemakers with pre-school children had been married an average of eight years while the homemakers with school age children had been married an average of 18 years. The children ranged in age from four months to 18 years old. The 12.5 percent of the families that did not own their own homes were all from the group with pre-school children. Although all of the homes were well equipped, the families that had been established the longest time had slightly more equipment. Half of the total group used time plans; the majority of the homemakers using time plans were homemakers with pre-school children. Homemakers in this study as well as previous studies most often listed food preparation as the homemaking activity they most enjoyed. Again, cleaning house was most often listed as the activity least enjoyed, followed by ironing. Improved housing, equipment, and methods have failed to change these attitudes in over a quarter of a century. The homemakers with pre-school children spent the greatest percentage of their time caring for children followed by meal preparation and clean-up; the homemakers with school age children spent the greatest percentage of their time on food preparation and clean-up. Both groups spent a little over two and a half hours on meal preparation and clean-up. Homemakers with school age children averaged 48 minutes a day on laundry, whereas homemakers with pre-school children averaged 70 minutes a day. Cleaning house averaged 63 minutes a day for homemakers with school age children and 45 minutes a day for homemakers with pre-school children. Homemakers with school age children averaged 39 minutes for shopping, whereas homemakers with pre-school children averaged 23 minutes. The homemakers with school age children averaged 8 hours and 45 minutes of rest per day, whereas the homemakers with pre-school children averaged 8 hours and 8 minutes. Homemakers with school age children spent more time eating meals, on personal care, and on entertaining and social activities, whereas homemakers with pre-school children derived much of their leisure time from unplanned coffee breaks and chatting with neighbors. Other than the great difference in the amount of time the two groups spent in caring for their children, (the homemakers with pre-school children spent 3 hours and 38 minutes while the homemakers with school age children spent 39 minutes), there was great similarity in the way the two groups used their time. Another finding is that there is little difference in the amount of time the homemaker spent on different homemaking activities at the time of this study in comparison to studies done during the past quarter of a century. Close

• 64. [Article] New 40Ar/39Ar age progression for the Louisville hot spot trail and implications for inter–hot spot motion

  In this study we present 42 new ⁴⁰Ar/³⁹Ar incremental heating age determinations that contribute to an updated age progression for the Louisville seamount trail. Louisville is the South Pacific counterpart ...

  Citation × Citation Citation Abstract Copy Title: New 40Ar/39Ar age progression for the Louisville hot spot trail and implications for inter–hot spot motion Author: Gee, Jeffrey S., Lonsdale, Peter F., Colwell, Lauren E., Koppers, Anthony A. P., Mahoney, John J., Duncan, Robert A., Gowen, Molly D. In this study we present 42 new ⁴⁰Ar/³⁹Ar incremental heating age determinations that contribute to an updated age progression for the Louisville seamount trail. Louisville is the South Pacific counterpart to the Hawaiian‐Emperor seamount trail, both trails representing intraplate volcanism over the same time interval (~80 Ma to present) and being examples of primary hot spot lineaments. Our data provide evidence for an age‐progressive trend from 71 to 21 Ma. Assuming fixed hot spots, this makes possible a direct comparison to the Hawaiian‐Emperor age progression and the most recent absolute plate motion (APM) model (WK08G) of Wessel and Kroenke (2008). We observe that for the Louisville seamount trail the measured ages are systematically older relative to both the WK08G model predictions and Hawaiian seamount ages, with offsets ranging up to 6 Myr. Taking into account the uncertainty about the duration of eruption and magmatic succession at individual Louisville volcanoes, these age offsets should be considered minimum estimates, as our sampling probably tended to recover the youngest lava flows. These large deviations point to either a contribution of inter–hot spot motion between the Louisville and Hawaiian hot spots or to a more easterly location of the Louisville hot spot than the one inferred in the WK08G model. Both scenarios are investigated in this paper, whereby the more eastern hot spot location (52.0°S, 134.5°W versus 52.4°S, 137.2°W) reduces the average age offset, but still results in a relatively large maximum offset of 3.7 Myr. When comparing the new ages to the APM models (S04P, S04G) by Steinberger et al. (2004) that attempt to compensate for the motion of hot spots in the Pacific (Hawaii) or globally (Hawaii, Louisville, Reunion and Walvis), the measured and predicted ages are more in agreement, showing only a maximum offset of 2.3 Myr with respect to the S04G model. At face value these more advanced APM models, which consider both plate and hot spot motions, therefore provide a better fit to the new Louisville age data. The fit is particularly good for seamounts younger than 50 Ma, a period for which there is little predicted motion for the Louisville hot spot and little inter–hot spot motion with Hawaii. However, discrepancies in the Louisville age‐distance record prior to 50 Ma indicate there is an extra source of inter–hot spot motion between Louisville and the other Pacific hot spots that was not corrected for in the global S04G model. Finally, based on six new ⁴⁰Ar/³⁹Ar age dates, the 169°W bend in the Louisville seamount trail seems to have formed at least 3 Myr before the formation of the Hawaiian‐Emperor bend. The timing of the most acute parts of both bends thus appears to be asynchronous, which would require other processes (e.g., plume motions) than a global plate motion change between 50 and 47 Ma to explain these two observations. Title: New 40Ar/39Ar age progression for the Louisville hot spot trail and implications for inter–hot spot motion Author: Gee, Jeffrey S., Lonsdale, Peter F., Colwell, Lauren E., Koppers, Anthony A. P., Mahoney, John J., Duncan, Robert A., Gowen, Molly D. In this study we present 42 new ⁴⁰Ar/³⁹Ar incremental heating age determinations that contribute to an updated age progression for the Louisville seamount trail. Louisville is the South Pacific counterpart to the Hawaiian‐Emperor seamount trail, both trails representing intraplate volcanism over the same time interval (~80 Ma to present) and being examples of primary hot spot lineaments. Our data provide evidence for an age‐progressive trend from 71 to 21 Ma. Assuming fixed hot spots, this makes possible a direct comparison to the Hawaiian‐Emperor age progression and the most recent absolute plate motion (APM) model (WK08G) of Wessel and Kroenke (2008). We observe that for the Louisville seamount trail the measured ages are systematically older relative to both the WK08G model predictions and Hawaiian seamount ages, with offsets ranging up to 6 Myr. Taking into account the uncertainty about the duration of eruption and magmatic succession at individual Louisville volcanoes, these age offsets should be considered minimum estimates, as our sampling probably tended to recover the youngest lava flows. These large deviations point to either a contribution of inter–hot spot motion between the Louisville and Hawaiian hot spots or to a more easterly location of the Louisville hot spot than the one inferred in the WK08G model. Both scenarios are investigated in this paper, whereby the more eastern hot spot location (52.0°S, 134.5°W versus 52.4°S, 137.2°W) reduces the average age offset, but still results in a relatively large maximum offset of 3.7 Myr. When comparing the new ages to the APM models (S04P, S04G) by Steinberger et al. (2004) that attempt to compensate for the motion of hot spots in the Pacific (Hawaii) or globally (Hawaii, Louisville, Reunion and Walvis), the measured and predicted ages are more in agreement, showing only a maximum offset of 2.3 Myr with respect to the S04G model. At face value these more advanced APM models, which consider both plate and hot spot motions, therefore provide a better fit to the new Louisville age data. The fit is particularly good for seamounts younger than 50 Ma, a period for which there is little predicted motion for the Louisville hot spot and little inter–hot spot motion with Hawaii. However, discrepancies in the Louisville age‐distance record prior to 50 Ma indicate there is an extra source of inter–hot spot motion between Louisville and the other Pacific hot spots that was not corrected for in the global S04G model. Finally, based on six new ⁴⁰Ar/³⁹Ar age dates, the 169°W bend in the Louisville seamount trail seems to have formed at least 3 Myr before the formation of the Hawaiian‐Emperor bend. The timing of the most acute parts of both bends thus appears to be asynchronous, which would require other processes (e.g., plume motions) than a global plate motion change between 50 and 47 Ma to explain these two observations. Close

• 65. [Article] A role for ceramide accumulation in age-related cardiac mitochondrial dysfunction

  Ceramides are a group of lipids in the sphingolipid family that are potent cell signaling molecules. Elevations in ceramide levels above the norm generally lead to apoptosis. Evidence from in vitro studies ...

  Citation × Citation Citation Abstract Copy Title: A role for ceramide accumulation in age-related cardiac mitochondrial dysfunction Author: Monette, Jeffrey S. Ceramides are a group of lipids in the sphingolipid family that are potent cell signaling molecules. Elevations in ceramide levels above the norm generally lead to apoptosis. Evidence from in vitro studies suggests that accumulation of ceramides within mitochondria leads to dysfunction of the mitochondria. This includes inhibition of the electron transport chain and release of reactive oxygen species (ROS). Large elevations of mitochondrial ceramide may also lead to death of the cell as they promote membrane permeability transition, which allows the release of cytochrome c and other apoptogenic factors. With age, cardiac mitochondria show a similar dysfunctional phenotype to that found in conditions of acute ceramide elevation. We therefore hypothesize that ceramides may be accumulating in cardiac mitochondria from aged animals. To elucidate the characteristics of the sphingolipidome, we developed both mitochondrial isolation techniques and tandem mass spectrometry assays to specifically and sensitively monitor mitochondrial sphingolipids. Using these techniques, it was found that mitochondria contain six distinct ceramide species with highly saturated lipid moieties. Using young (3-6 months old; which corresponds to a post-adolescent human) and old (24 to 28 months old; which corresponds to an elderly human) Fischer 344 rat hearts, we found that aging leads to a significant increase in total mitochondrial ceramides (32%, p < 0.03), with C₁₆-, C₁₈-, and C₂₄:₁-ceramides showing the largest percent increases (72.3%, 73.4%, and 77.7%, respectively, p < 0.05). Furthermore, the age-associated elevation in ceramide levels correlated to a 28% decrease in the activity of complex IV of the electron transport chain (p < 0.05), which could be replicated in vitro by inducing a ceramide accumulation in mitochondria isolated from young animals. Mitochondria do not contain enzymes for de novo ceramide biosynthesis, rather, these organelles have sphingomyelinases, a family of enzymes that cleave the phosphorylcholine headgroup from nascent pools of sphingomyelin. Specifically, mitochondria contain the magnesium-requiring isoform of sphingomyelinase with a neutral pH optima (nSMase). Recent work has shown that nSMase activity is inversely regulated by glutathione status. Because cardiac mitochondrial glutathione (mGSH) declines by up to 60% with age, we hypothesized that the loss in mGSH leads to an increase in ceramides through the upregulation of nSMase. To determine whether loss of mGSH plays a role in the regulation of mitochondrial nSMase activity, mGSH levels were depleted by treating freshly isolated hepatocytes with 3-hydroxy-4-pentenoate (3HP). It was found that 3HP rapidly depleted mGSH in a concentration-dependent manner (EC₅₀ = 232 μM, p < 0.05). Moreover, this depletion led to an increase in nSMase activity (24 ± 3% at 250 μM 3HP, p < 0.05), and an increase in total ceramide levels (27%, p < 0.05). These findings suggest that mGSH status plays a critical role in the maintenance of ceramide levels within mitochondria. Furthermore, because nSMase activity is regulated by mGSH levels, we hypothesized that any agent promoting an increase in mGSH would reverse the ceramide accumulation seen in cardiac mitochondria from aged animals. Lipoic acid (LA) is a naturally occurring dithiol compound used for many years as an anti-inflammatory agent. LA-supplementation has been shown to increase cellular and mGSH by increasing cellular cysteine levels in the aging heart. In order to determine whether LA reverses the age-associated ceramidosis in cardiac mitochondria, young and old F344 rats were pair-fed LA [0.2% (w/w) in the diet] against controls for two weeks and cardiac mitochondria were subsequently isolated and analyzed. It was found that LA-treatment reversed the age-associated decline in mGSH levels [decreased 43% with age (p < 0.05)], and reduced nSMase activity [increased 103% with age (p < 0.05)]. Ceramide levels were reduced [elevated 32% with age (p < 0.03)] so that they were no longer different from young controls and complex IV activity restored t youthful levels [declined 28% with age (p < 0.05)]. In conclusion, this dissertation provides evidence to support a new mechanism that explains, at least in part, the progression of mitochondrial dysfunction in the aging heart, and may also contribute to understanding the age-related loss of cardiomyocytes. It also provides mechanistic insights into the overall health benefits of LA supplementation and supports its use as a safe, natural, and "age-essential" micronutrient. Title: A role for ceramide accumulation in age-related cardiac mitochondrial dysfunction Author: Monette, Jeffrey S. Ceramides are a group of lipids in the sphingolipid family that are potent cell signaling molecules. Elevations in ceramide levels above the norm generally lead to apoptosis. Evidence from in vitro studies suggests that accumulation of ceramides within mitochondria leads to dysfunction of the mitochondria. This includes inhibition of the electron transport chain and release of reactive oxygen species (ROS). Large elevations of mitochondrial ceramide may also lead to death of the cell as they promote membrane permeability transition, which allows the release of cytochrome c and other apoptogenic factors. With age, cardiac mitochondria show a similar dysfunctional phenotype to that found in conditions of acute ceramide elevation. We therefore hypothesize that ceramides may be accumulating in cardiac mitochondria from aged animals. To elucidate the characteristics of the sphingolipidome, we developed both mitochondrial isolation techniques and tandem mass spectrometry assays to specifically and sensitively monitor mitochondrial sphingolipids. Using these techniques, it was found that mitochondria contain six distinct ceramide species with highly saturated lipid moieties. Using young (3-6 months old; which corresponds to a post-adolescent human) and old (24 to 28 months old; which corresponds to an elderly human) Fischer 344 rat hearts, we found that aging leads to a significant increase in total mitochondrial ceramides (32%, p < 0.03), with C₁₆-, C₁₈-, and C₂₄:₁-ceramides showing the largest percent increases (72.3%, 73.4%, and 77.7%, respectively, p < 0.05). Furthermore, the age-associated elevation in ceramide levels correlated to a 28% decrease in the activity of complex IV of the electron transport chain (p < 0.05), which could be replicated in vitro by inducing a ceramide accumulation in mitochondria isolated from young animals. Mitochondria do not contain enzymes for de novo ceramide biosynthesis, rather, these organelles have sphingomyelinases, a family of enzymes that cleave the phosphorylcholine headgroup from nascent pools of sphingomyelin. Specifically, mitochondria contain the magnesium-requiring isoform of sphingomyelinase with a neutral pH optima (nSMase). Recent work has shown that nSMase activity is inversely regulated by glutathione status. Because cardiac mitochondrial glutathione (mGSH) declines by up to 60% with age, we hypothesized that the loss in mGSH leads to an increase in ceramides through the upregulation of nSMase. To determine whether loss of mGSH plays a role in the regulation of mitochondrial nSMase activity, mGSH levels were depleted by treating freshly isolated hepatocytes with 3-hydroxy-4-pentenoate (3HP). It was found that 3HP rapidly depleted mGSH in a concentration-dependent manner (EC₅₀ = 232 μM, p < 0.05). Moreover, this depletion led to an increase in nSMase activity (24 ± 3% at 250 μM 3HP, p < 0.05), and an increase in total ceramide levels (27%, p < 0.05). These findings suggest that mGSH status plays a critical role in the maintenance of ceramide levels within mitochondria. Furthermore, because nSMase activity is regulated by mGSH levels, we hypothesized that any agent promoting an increase in mGSH would reverse the ceramide accumulation seen in cardiac mitochondria from aged animals. Lipoic acid (LA) is a naturally occurring dithiol compound used for many years as an anti-inflammatory agent. LA-supplementation has been shown to increase cellular and mGSH by increasing cellular cysteine levels in the aging heart. In order to determine whether LA reverses the age-associated ceramidosis in cardiac mitochondria, young and old F344 rats were pair-fed LA [0.2% (w/w) in the diet] against controls for two weeks and cardiac mitochondria were subsequently isolated and analyzed. It was found that LA-treatment reversed the age-associated decline in mGSH levels [decreased 43% with age (p < 0.05)], and reduced nSMase activity [increased 103% with age (p < 0.05)]. Ceramide levels were reduced [elevated 32% with age (p < 0.03)] so that they were no longer different from young controls and complex IV activity restored t youthful levels [declined 28% with age (p < 0.05)]. In conclusion, this dissertation provides evidence to support a new mechanism that explains, at least in part, the progression of mitochondrial dysfunction in the aging heart, and may also contribute to understanding the age-related loss of cardiomyocytes. It also provides mechanistic insights into the overall health benefits of LA supplementation and supports its use as a safe, natural, and "age-essential" micronutrient. Close

• 66. [Article] Accelerated food source location in aging Drosophila

  Adequate energy stores are essential for animal survival, and sophisticated neuroendocrine mechanisms evolved to stimulate foraging in response to nutrient deprivation. Food search behavior is usually ...

  Citation × Citation Citation Abstract Copy Title: Accelerated food source location in aging Drosophila Author: Egenriether, Sada Adequate energy stores are essential for animal survival, and sophisticated neuroendocrine mechanisms evolved to stimulate foraging in response to nutrient deprivation. Food search behavior is usually investigated in young animals, and it is not known how aging alters this behavior. To address this question in Drosophila, we compared the ability to locate food by olfaction in young and old flies using a food-filled trap. As aging is associated with decline in motor functions, learning, and memory, we expected that aged flies would take longer to enter the food trap than their young counterparts. Surprisingly, old flies located food with significantly shorter latency than the young ones. We determined that old flies have significantly lower fat reserves and are more susceptible to starvation than young flies. Food search latency was shortened in young wild type flies that were starved until their fat was depleted. We also determined that the difference in food finding latency (FFL) between young and old flies is mediated by insulin signaling. Together, our data suggest that shorter FFL in old flies is linked to age-dependent differences in metabolic status. Title: Accelerated food source location in aging Drosophila Author: Egenriether, Sada Adequate energy stores are essential for animal survival, and sophisticated neuroendocrine mechanisms evolved to stimulate foraging in response to nutrient deprivation. Food search behavior is usually investigated in young animals, and it is not known how aging alters this behavior. To address this question in Drosophila, we compared the ability to locate food by olfaction in young and old flies using a food-filled trap. As aging is associated with decline in motor functions, learning, and memory, we expected that aged flies would take longer to enter the food trap than their young counterparts. Surprisingly, old flies located food with significantly shorter latency than the young ones. We determined that old flies have significantly lower fat reserves and are more susceptible to starvation than young flies. Food search latency was shortened in young wild type flies that were starved until their fat was depleted. We also determined that the difference in food finding latency (FFL) between young and old flies is mediated by insulin signaling. Together, our data suggest that shorter FFL in old flies is linked to age-dependent differences in metabolic status. Close

• 67. [Article] Investigating the age-related loss of endoplasmic reticulum stress response

  The endoplasmic reticulum (ER) is a crucial organelle in the cell where protein folding and processing occurs, and conditions that negatively affect ER functions are highly detrimental to the cell. The ...

  Citation × Citation Citation Abstract Copy Title: Investigating the age-related loss of endoplasmic reticulum stress response Author: Fallahi, Anahita The endoplasmic reticulum (ER) is a crucial organelle in the cell where protein folding and processing occurs, and conditions that negatively affect ER functions are highly detrimental to the cell. The accumulation of unfolded/misfolded proteins in the ER leads to a condition known as ER Stress. The ER has developed various pro-survival and pro-apoptosis signaling pathways that attempt to cope with this stress. ER stress is relevant to many clinical studies and has been linked to a variety of age-related diseases, including Huntington’s, Alzheimer’s, Parkinson’s and heart disease. Despite these findings, the manner in which ER stress response is altered with age hasn’t been thoroughly studied and constitutes a gap in knowledge. In this study, we investigated the age-related loss of ER stress response in young and old rats. Our results suggest that, in both young and old cells, the pro-apoptosis pathway which utilizes the transcription factor, CHOP, remains intact with age. However, the pro-survival pathway acting through PERK/Nrf2 and the phase II detoxification enzyme NQO1 show elevated activity in the young cells, but a loss of function in the old. These results suggest that stresses which would not cause cell death in young individuals may induce cell death in the elderly. Title: Investigating the age-related loss of endoplasmic reticulum stress response Author: Fallahi, Anahita The endoplasmic reticulum (ER) is a crucial organelle in the cell where protein folding and processing occurs, and conditions that negatively affect ER functions are highly detrimental to the cell. The accumulation of unfolded/misfolded proteins in the ER leads to a condition known as ER Stress. The ER has developed various pro-survival and pro-apoptosis signaling pathways that attempt to cope with this stress. ER stress is relevant to many clinical studies and has been linked to a variety of age-related diseases, including Huntington’s, Alzheimer’s, Parkinson’s and heart disease. Despite these findings, the manner in which ER stress response is altered with age hasn’t been thoroughly studied and constitutes a gap in knowledge. In this study, we investigated the age-related loss of ER stress response in young and old rats. Our results suggest that, in both young and old cells, the pro-apoptosis pathway which utilizes the transcription factor, CHOP, remains intact with age. However, the pro-survival pathway acting through PERK/Nrf2 and the phase II detoxification enzyme NQO1 show elevated activity in the young cells, but a loss of function in the old. These results suggest that stresses which would not cause cell death in young individuals may induce cell death in the elderly. Close

• 68. [Article] Perceptions of residential grab bars among community dwelling seniors

  Despite the perceived importance of grab bars to facilitate aging-in-place and healthy aging, many community-dwelling older adults do not have them installed. The aim of this study was to investigate predictors ...

  Citation × Citation Citation Abstract Copy Title: Perceptions of residential grab bars among community dwelling seniors Author: Thrall, Patti L. Despite the perceived importance of grab bars to facilitate aging-in-place and healthy aging, many community-dwelling older adults do not have them installed. The aim of this study was to investigate predictors of grab bar installation among well-educated community dwelling seniors. Data was collected quantitatively through an electronic survey of Oregon residents 50 years of age and older. The research analysis was completed using logistic regression with SPSS and qualitative analysis for the open questions. Title: Perceptions of residential grab bars among community dwelling seniors Author: Thrall, Patti L. Despite the perceived importance of grab bars to facilitate aging-in-place and healthy aging, many community-dwelling older adults do not have them installed. The aim of this study was to investigate predictors of grab bar installation among well-educated community dwelling seniors. Data was collected quantitatively through an electronic survey of Oregon residents 50 years of age and older. The research analysis was completed using logistic regression with SPSS and qualitative analysis for the open questions. Close

• 69. [Article] Sediment reservoir dynamics on steepland valley floors : influence of network structure and effects of inherited ages

  Sediment deposit ages inferred from radiocarbon dating of stream bank material were used to estimate residence times of valley-floor deposits in headwater valleys of the Oregon Coast Range, USA. Inherited ...

  Citation × Citation Citation Abstract Copy Title: Sediment reservoir dynamics on steepland valley floors : influence of network structure and effects of inherited ages Author: Frueh, Walter Terry Sediment deposit ages inferred from radiocarbon dating of stream bank material were used to estimate residence times of valley-floor deposits in headwater valleys of the Oregon Coast Range, USA. Inherited ages of radiocarbon-dated material, i.e., time between carbon fixation in wood and its incorporation in a sediment deposit, can result in over-estimation of the ages of those deposits and, hence, the residence times of sediment within those units. Calibrated radiocarbon dates of 126 charcoal pieces sampled from Knowles Creek were used to estimate the distribution of inherited ages in fourteen depositional units representing three deposit types: fluvial fines, fluvial gravels, and debris flows. Within a depositional unit, the inherited age distribution of a piece of charcoal was estimated by convolving its calibrated age distribution with that of the piece of charcoal with the smallest weighted-mean calibrated age (i.e., an approximation of a unit's date of deposition) within that unit. All inherited age distributions for a particular deposit type were then added and normalized to provide a probability distribution of inherited ages for that deposit type. Probability distributions of inherited ages average 688, 1506, and 666 yr for fluvial fines, fluvial gravels, and debris flow units, respectively. Curves were fit to inherited age distributions for each deposit type. These curve fits were then convolved with deposit age distributions (i.e., equal to calibrated age distributions of woody material sampled from stream banks) of samples from Bear Creek (Lancaster and Casebeer, 2007) to correct these deposit ages for inherited age. This convolution gives a corrected deposit age. In cases in which means of corrected deposit age distributions for an upper unit were older than those of a lower unit within a stratigraphic column, the upper sample’s corrected deposit age distribution was set to that of the youngest lower in the stratigraphic section. Convolution shifted individual deposit age distributions towards zero and increased their standard deviation by an average of 365%. However, convolution decreased the standard deviations of normalized probability distribution functions of deposit ages inferred from many samples from 1340 to 1197 yr, and from 471 to 416 yr for lower and upper reaches, respectively, of the Bear Creek valley in the Oregon Coast Range. Convolution decreased estimates of mean deposit ages from 1296 to 1051 yr, and from 308 to 245 yr for lower and upper reaches, respectively, of the Bear Creek. Estimates of percentages of basin denudation passing through each reach's deposit ("trapping efficiency") increased from 11.6% to 14.4%, and from 25.4% to 31.9% for lower and upper Bear Creek, respectively. However, basic shapes of residence time distributions and, thus, inferences regarding removal of sediment from the reaches did not change after deposit dates were corrected. Sediment residence times in the lower Bear Creek valley are exponentially distributed, which implies that all sediment has a uniform probability of evacuation from deposits, whereas the power-law-distributed residence times in upper Bear imply preferential evacuation of younger deposits and preservation of older deposits. Much of the sediment transported onto valley floors via debris flows is deposited, and then is evacuated over longer times. Volumes and residence times of stored sediment in these deposits at the transition from debris flow to fluvial evacuation, and their associated width of valley floors, vary throughout a network. Export volumes and frequencies from tributaries are controls on deposit volumes and may control valley widening of mainstem valley floors. In addition, closely spaced tributaries may exert composite effects on valley floor landforms. It is hypothesized that the volumes of sediment stored at confluences increases with contributing watershed area of tributaries to the point where tributary slopes are low enough to cause most debris flows to be deposited within tributary valleys instead of in the mainstem valley. In four ~1 km reaches with contributing watershed areas of 0.3 to 5.0 km², field surveys provided measures of width of valley floors and volume of deposits, and radiocarbon dating of charcoal provided residence times of sediment in these deposits. Mean residence times of reaches vary between 1.1 and 2.5 kyr. Exponential distributions fit to residence times within two of the reaches imply evacuation of sediment independent of deposit ages. Power-law fits to residence times of the other two reaches imply age-dependent evacuation of deposits. Distribution shapes of residence times, and their means, do not vary systematically with contributing watershed area of mainstems. Mean width of mainstem valley floors increases with contributing watershed areas of both mainstems and their respective tributaries. Volumes of sediment stored on the valley floor increase with contributing areas of mainstems, and these volumes at tributary junctions peaked at tributary contributing areas of ~0.1 km². Percentage of basin denudation entering storage decreases with contributing area of mainstem. This decrease may be due to increasing percentages of sediment supply via fluvial transport for larger watersheds, and much, if not most, of this supply routes through the system quickly. Title: Sediment reservoir dynamics on steepland valley floors : influence of network structure and effects of inherited ages Author: Frueh, Walter Terry Sediment deposit ages inferred from radiocarbon dating of stream bank material were used to estimate residence times of valley-floor deposits in headwater valleys of the Oregon Coast Range, USA. Inherited ages of radiocarbon-dated material, i.e., time between carbon fixation in wood and its incorporation in a sediment deposit, can result in over-estimation of the ages of those deposits and, hence, the residence times of sediment within those units. Calibrated radiocarbon dates of 126 charcoal pieces sampled from Knowles Creek were used to estimate the distribution of inherited ages in fourteen depositional units representing three deposit types: fluvial fines, fluvial gravels, and debris flows. Within a depositional unit, the inherited age distribution of a piece of charcoal was estimated by convolving its calibrated age distribution with that of the piece of charcoal with the smallest weighted-mean calibrated age (i.e., an approximation of a unit's date of deposition) within that unit. All inherited age distributions for a particular deposit type were then added and normalized to provide a probability distribution of inherited ages for that deposit type. Probability distributions of inherited ages average 688, 1506, and 666 yr for fluvial fines, fluvial gravels, and debris flow units, respectively. Curves were fit to inherited age distributions for each deposit type. These curve fits were then convolved with deposit age distributions (i.e., equal to calibrated age distributions of woody material sampled from stream banks) of samples from Bear Creek (Lancaster and Casebeer, 2007) to correct these deposit ages for inherited age. This convolution gives a corrected deposit age. In cases in which means of corrected deposit age distributions for an upper unit were older than those of a lower unit within a stratigraphic column, the upper sample’s corrected deposit age distribution was set to that of the youngest lower in the stratigraphic section. Convolution shifted individual deposit age distributions towards zero and increased their standard deviation by an average of 365%. However, convolution decreased the standard deviations of normalized probability distribution functions of deposit ages inferred from many samples from 1340 to 1197 yr, and from 471 to 416 yr for lower and upper reaches, respectively, of the Bear Creek valley in the Oregon Coast Range. Convolution decreased estimates of mean deposit ages from 1296 to 1051 yr, and from 308 to 245 yr for lower and upper reaches, respectively, of the Bear Creek. Estimates of percentages of basin denudation passing through each reach's deposit ("trapping efficiency") increased from 11.6% to 14.4%, and from 25.4% to 31.9% for lower and upper Bear Creek, respectively. However, basic shapes of residence time distributions and, thus, inferences regarding removal of sediment from the reaches did not change after deposit dates were corrected. Sediment residence times in the lower Bear Creek valley are exponentially distributed, which implies that all sediment has a uniform probability of evacuation from deposits, whereas the power-law-distributed residence times in upper Bear imply preferential evacuation of younger deposits and preservation of older deposits. Much of the sediment transported onto valley floors via debris flows is deposited, and then is evacuated over longer times. Volumes and residence times of stored sediment in these deposits at the transition from debris flow to fluvial evacuation, and their associated width of valley floors, vary throughout a network. Export volumes and frequencies from tributaries are controls on deposit volumes and may control valley widening of mainstem valley floors. In addition, closely spaced tributaries may exert composite effects on valley floor landforms. It is hypothesized that the volumes of sediment stored at confluences increases with contributing watershed area of tributaries to the point where tributary slopes are low enough to cause most debris flows to be deposited within tributary valleys instead of in the mainstem valley. In four ~1 km reaches with contributing watershed areas of 0.3 to 5.0 km², field surveys provided measures of width of valley floors and volume of deposits, and radiocarbon dating of charcoal provided residence times of sediment in these deposits. Mean residence times of reaches vary between 1.1 and 2.5 kyr. Exponential distributions fit to residence times within two of the reaches imply evacuation of sediment independent of deposit ages. Power-law fits to residence times of the other two reaches imply age-dependent evacuation of deposits. Distribution shapes of residence times, and their means, do not vary systematically with contributing watershed area of mainstems. Mean width of mainstem valley floors increases with contributing watershed areas of both mainstems and their respective tributaries. Volumes of sediment stored on the valley floor increase with contributing areas of mainstems, and these volumes at tributary junctions peaked at tributary contributing areas of ~0.1 km². Percentage of basin denudation entering storage decreases with contributing area of mainstem. This decrease may be due to increasing percentages of sediment supply via fluvial transport for larger watersheds, and much, if not most, of this supply routes through the system quickly. Close

• 70. [Article] Fecundity and longevity in Tribolium castaneum : a selection experiment

  Recent experimental and theoretical work has examined the possible genetic causes of senescence. These are reviewed, and four types of factors are found to be responsible for the evolution of senescence ...

  Citation × Citation Citation Abstract Copy Title: Fecundity and longevity in Tribolium castaneum : a selection experiment Author: Treneman, Nancy C. Recent experimental and theoretical work has examined the possible genetic causes of senescence. These are reviewed, and four types of factors are found to be responsible for the evolution of senescence and age specific fecundity curves: 1. Age specific mortality schedules, 2.Density dependent factors, 3. Density independent factors, 4. Random fluctuations in environmental conditions. A discussion of al leles with different age specific effects explores their behavior under a variety of mortal ity schedules. An experiment involving natural and artificial selection for high fecundity at 10 and 100 days of age in a laboratory population of Iriloilan LAatamgam resulted in significant increases in 100 day fecundity in al 1 lines. No change in 10 day fecundity was seen in any I ine. Percent mortal ity was not changed by selection. The heritabil ity of fecundity at 10 and 100 days was measured: heritabil ity was estimated to be .53 + .35 for 10 day fecundity and zero at 100 days. These results are shown to support the hypothesis that this I, cAliamlam population is polymorphic with respect to age specific fecundity distributions and that the life history strategy of this organism has been molded by fluctuating juvenile mortality. Title: Fecundity and longevity in Tribolium castaneum : a selection experiment Author: Treneman, Nancy C. Recent experimental and theoretical work has examined the possible genetic causes of senescence. These are reviewed, and four types of factors are found to be responsible for the evolution of senescence and age specific fecundity curves: 1. Age specific mortality schedules, 2.Density dependent factors, 3. Density independent factors, 4. Random fluctuations in environmental conditions. A discussion of al leles with different age specific effects explores their behavior under a variety of mortal ity schedules. An experiment involving natural and artificial selection for high fecundity at 10 and 100 days of age in a laboratory population of Iriloilan LAatamgam resulted in significant increases in 100 day fecundity in al 1 lines. No change in 10 day fecundity was seen in any I ine. Percent mortal ity was not changed by selection. The heritabil ity of fecundity at 10 and 100 days was measured: heritabil ity was estimated to be .53 + .35 for 10 day fecundity and zero at 100 days. These results are shown to support the hypothesis that this I, cAliamlam population is polymorphic with respect to age specific fecundity distributions and that the life history strategy of this organism has been molded by fluctuating juvenile mortality. Close