In everyday life memory is commonly used in the completion of future intentions, such as remembering to attend a meeting or remembering to make a purchase at a particular time or place. The ability to remember to complete future intentions plays an important role in older adults maintaining independent living within the community (Cherry & LeCompte, 1999). The studies presented in this thesis evolved out of the lack of current understanding about which component processes involved in remembering future intentions are most susceptible to the effects of aging. In order to investigate these processes, a computer-based analogue of a real-life task was developed (the Virtual Street) that enabled participants to complete a series of intentions (shopping errands) during a simulated visit to a shopping centre. There were two main objectives of this thesis. The first objective was to examine whether the Virtual Street shopping task was appropriate for assessing older and younger adults ability to remember to complete delayed intentions and whether the task had better ecological and face validity than current assessment measures. The second objective was to identify the cognitive processes involved in the task that were vulnerable to the effects of aging, and whether the process of recognising the cues or the memory search of the intention content would be affected. In order to examine these cognitive processes, various factors were manipulated in ways designed to be analogous to real-world situations, which were hypothesized to be sensitive to the effects of aging. These factors include: a change in the location where an intention can be realised (Study 1), the opportunity to learn the intentions (Study 2), the familiarity of the shopping environment (Study 3), and the presence of distractions (Study 4). Overall, the results from the four studies demonstrated that older adults have difficulty remembering delayed intentions, even when the test uses naturalistic stimuli, the tasks are familiar, and they are able to move at their own pace. Furthermore, the results from Study 2 demonstrated that the memory search component but not cue detection was affected in older persons when they were given fewer trials to learn the shopping errands, possibly due to the accessibility of the cue-intention associations may be impaired in older adults. There was no age specific effect on cue detection or memory search in either an unfamiliar street environment (Study 3) or one with increased levels of irrelevant auditory and visual noise (distraction condition, Study 4). In the interruption condition of Study 4, however, cue detection but not memory search was disproportionately affected in older adults after filled interruptions, suggesting that the capacity for self-initiated reinstatement of working memory is reduced in old age. In general, the Virtual Street task was to be a practical means of examining younger and older adults ability to remember to complete delayed intentions. The Virtual Street task also provided an opportunity for behavioural observation of real-life skills and cognitive abilities, within a controlled context. It is hoped that the Virtual Street shopping task will continue to be developed into an ecologically valid measure of assessing older adults memory functioning.

研究目的：探索大陸人口結構老化趨勢及人口老化對大陸社會。經濟發展之影響，中共有無足夠條件解決進入老年型社會後所面臨之老人種種社會問題，大陸退休養老制度現狀及缺失為何。及對大陸未來解決人口老化問題之評估。研究內容：1.中共人口政策對中國大陸人口發展之影響。2.大陸人口結構老化趨勢成因及特徵。3.人口老化對大陸經濟之影響。4.人口老化對大陸社會之衝擊。5.中共對人口老化問題之認識與因應措施。6.大陸老年退休養老事業。7.大陸解決人口老化之經濟條件。研究結果：1.除了生活水平及醫療技術提高外，中共努力推行旨在減少生育之人口政策為大陸人口結構趨於老化之主因。2.推測大陸六十五歲老年人口在本世紀末將達7.22%進入老年型社會。大陸老齡人口及人口老化程度將在2030年左右達到頂峰。3.大陸為發展中國家，在經濟尚未達到一定水平，社會福利制度尚未健全，人口就已老化，對社會。經濟等問題將較其他先進國家嚴重。4.要解決大陸人口老化老年退休養老問題，除須繼續實行開放改革，努力發展經濟提供充份之物質能力條件外，必須改革目前的退休。養老規定，健全社會福利保障制度。

Attempts to understand the effects of ageing on the condition of a synovial joint. Knee joints of individuals with no known history of joint disease were examined and the pattern of cartilage damage was mapped macroscopically in a manner that allowed quantitation of the affected areas. / Bibliography: leaves 267-277. / vi, 277 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Pathology, 1993

<p>Äldre yrkesverksamma är en ökande grupp på arbetsmarknaden. Det är inte ovanligt att stereotypa uppfattningar kring denna grupp resulterar i åldersdiskriminering. Det är även känt att människor förändras, både till det bättre och sämre, genom åren och att detta påverkar individens yrkesutövande. Sex grundskolelärare intervjuades med syftet att beskriva och förstå hur de ser på åldrandet, pensionen, hur de upplever att de utvecklats under åren samt hur de upplever att omgivningen ser på dem. Erfarenheter ansågs vara det mest positiva med att vara äldre medan distansen till eleverna var det negativa. Åldrandet ansågs medföra fysiska försämringar, men samtidigt upplevdes bättre människokännedom och ökad säkerhet i rollen som lärare. Pensionen lockade för vissa men arbetet upplevdes vara en viktig trygghet i livet.</p>

Aging is associated with increases in regional and systemic vascular resistance and arterial blood pressure. One possible mechanism through which these age-associated alterations occur is enhanced vasoconstrictor responsiveness, or alterations in the structural properties of the resistance vasculature. We hypothesized that stiffness and vasoconstriction would be greater in skeletal muscle arterioles from old rats, and that endurance exercise training would ameliorate the associated with aging alterations. METHODS: Young sedentary (YS; 4 months), old sedentary (OS; 24 months), young trained (YT) and old trained (OT) male Fischer 344 rats were used. Training modality was treadmill exercise at 15 m/min up a 15o incline, 5 days/wk for 12wks. Skeletal muscle first-order arterioles were isolated for in vitro experimentation. Intraluminal diameter was measured in response to the cumulative addition of endothelin-1, norepinephrine, KCl, and isoproterenol. Stiffness was measure by examining the arterioles' stress and strain relation to increased luminal pressure in Ca++ free solution. RESULTS: Skeletal muscle arterioles had augmented vasoconstriction to endothelin-1 and norepinephrine. Adrenergic vasodilation was diminished in aged rat arterioles. Stiffness increased with age. Exercise training ameliorated the age-associated changes in stiffness and norepinephrine vasoconstriction. Exercise training did not alter endothelin-1 vasoconstriction or adrenergic vasodilation. CONCLUSIONS: These findings suggest that enhanced vascular sensitivity to vasoconstrictors and increased arteriole stiffness may play a role in the increase in skeletal muscle and systemic vascular resistance and, thus, contribute to the elevated blood pressure which occurs in aging humans. These results also demonstrate some of the cardioprotective effects of exercise training.

Aging is associated with increases in regional and systemic vascular resistance and impaired ability to increase blood flow to active muscles during exercise. Aging enhances vasoconstrictor responsiveness in both humans and animals, and an increase in Angiotensin II-induced vasoconstriction is one possible mechanism for old age-associated increase in muscle vascular resistance. The purpose of this study was to determine 1) whether aging alters Ang II-induced vasoconstriction, 2) whether exercise training attenuates the age-associated alteration in Ang II-mediated vasoconstriction, and 3) the mechanism(s) through which aging and exercise training alter Ang II-induced vasoconstriction in rat skeletal muscle arterioles. Male Fischer 344 rats were assigned to 4 groups: Young sedentary (YS; 4 months), old sedentary (OS; 24 months), young trained (YT) and old trained (OT). Exercise-trained groups performed treadmill exercises for 60 min/day at 15 m/min, on a 15º incline for 5 days/week for 10-12 weeks. First-order (1A) arterioles were isolated from soleus and gastrocnemius muscles for in vitro experimentation. Intraluminal diameter changes were determined in response to the cumulative addition of Ang II (3×10-11 - 3×10-5 M). Ang II dose responses were then determined following the removal of endothelium and treatment with NG-nitro-L-arginine methyl ester (L-NAME, 10-5 M), a nitric oxide synthase (NOS) inhibitor. Ang II-induced vasoconstriction was augmented in the aged skeletal muscle arterioles, both in soleus and gastrocnemius muscles, and age-associated increases in Ang II-induced vasoconstriction were abolished with the removal of endothelium and with L-NAME. Exercise training ameliorated the age-induced increase in Ang II-vasoconstriction, and this alteration was eliminated by the removal of endothelium and with NOS inhibition. These findings suggest that aging enhances Ang II-induced vasoconstrictor responses in the arterioles from both soleus, high oxidative, and white portion of gastrocnemius, low oxidative glycolytic muscles, and this age-associated change occurs through an endothelium-dependent NOS signaling pathway. These results also demonstrated that exercise training can ameliorate the age-associated increase in Ang II vasoconstriction in the arterioles from both high oxidative and low oxidative glycolytic muscles through an endothelium-mediated NOS mechanism.

The optical density of human macular pigment was measured for 50 observers ranging in age from 10 to 90 years. The psychophysical method required adjusting the radiance of a 1°, monochromatic light (400–550 nm) to minimize flicker (15 Hz) when presented in counterphase with a 460 nm standard. This test stimulus was presented superimposed on a broad-band, short-wave background. Macular pigment density was determined by comparing sensitivity under these conditions for the fovea, where macular pigment is maximal, and 5° temporally. This difference spectrum, measured for 12 observers, matched Wyszecki and Stiles's standard density spectrum for macular pigment. To study variation in macular pigment density for a larger group of observers, measurements were made at only selected spectral points (460, 500 and 550 nm). The mean optical density at 460 nm for the complete sample of 50 subjects was 0.39. Substantial individual differences in density were found (ca. 0.10–0.80), but this variation was not systematically related to age.

Äldre yrkesverksamma är en ökande grupp på arbetsmarknaden. Det är inte ovanligt att stereotypa uppfattningar kring denna grupp resulterar i åldersdiskriminering. Det är även känt att människor förändras, både till det bättre och sämre, genom åren och att detta påverkar individens yrkesutövande. Sex grundskolelärare intervjuades med syftet att beskriva och förstå hur de ser på åldrandet, pensionen, hur de upplever att de utvecklats under åren samt hur de upplever att omgivningen ser på dem. Erfarenheter ansågs vara det mest positiva med att vara äldre medan distansen till eleverna var det negativa. Åldrandet ansågs medföra fysiska försämringar, men samtidigt upplevdes bättre människokännedom och ökad säkerhet i rollen som lärare. Pensionen lockade för vissa men arbetet upplevdes vara en viktig trygghet i livet.

Nicotine, the major psychoactive ingredient of tobacco smoke, underlies numerous effects by activating neuronal nicotinic acetylcholine receptors. Both in vitro and in vivo studies suggest that nicotine is neuroprotective and improves cognitive performance. Epidemiology studies show that smoking is negatively correlated with the incidence of Parkinson's disease and Alzheimer's disease. Postmortem research and neuroimaging studies show that loss of nicotinic binding sites in the brain is the major feature of neurodegenerative diseases related to dementia and cognitive impairment. Caloric restriction, a regimen that extends the lifespan in all mammalian species studied so far including rodents and primates, is a highly regulated response to food deprivation. It is believed that the longevity effect of caloric restriction is mediated by SIRT1, a NAD-dependent deacetylase, and its related genes. Nicotine's effect on body weight could also lead to weight loss by decreasing caloric absorption consumption. The goal of this study was to find the possible correlation between nicotine's effects and the activation of SIRT1 and its related genes. Using beta2-/- mice that lack high affinity beta2 nicotinic acetylcholine receptors (nAChRs), we first demonstrated that beta2* nAChRs do not directly regulate expression of survival genes. However, we found that loss of beta2* nAChRs could result in augmented cellular stress, which indirectly increased expression of SIRT1, Nampt, and Ku70, possibly as an adaptive response to provide protection against neurodegeneration. We also found that loss of endogenous activation of beta2* nAChRs had less effect on synaptic connections but strongly impaired survival of hippocampal GABAergic neurons. To activate beta2* nAChRs in normal mice, we administered nicotine through drinking water. In a short-term exposure study, we determined the dose of nicotine to be used in young adult mice, and found that chronic nicotine treatment was anxiolytic, decreased caloric consumption, increased nAChR binding sites, and most importantly, increased expression of SIRT1 and its related genes. Finally, we compared long-term nicotine treatment with caloric restriction in middle-aged mice to examine their effects to brain aging, and our results indicated that in mice long term caloric restriction and nicotine treatment both tend to improve memory in aging mice, but appear to act through different mechanisms.

Modeling of the time-dependent behavior of cement paste has always been a difficulty. In the past, viscoelastic behavior of cementitious materials has been primarily attributed to the viscoelastic properties of C-S-H components. Recent experimental results show that C-S-H may not exhibit as much creep and relaxation as previously thought. This requires new consideration of different mechanisms leading to the viscoelastic behavior of cement paste. Thus the objective of this thesis is to build a computational model using finite element method to predict the viscoelastic behavior of cement paste, and using this model, virtual tests can be carried out to improve understanding of the mechanisms of viscoelastic behavior. The primary finding from this thesis is that the apparent viscoelastic behavior due to dissolution of load bearing phases is substantial. The dissolution process occurring during the hydration reaction can change the stress distribution inside cementitious materials, resulting in an apparent viscoelastic behavior of the whole cementitious materials. This finding requires new consideration of mechanisms of time-dependent behavior of cementitious materials regarding the dissolution process of cement paste.