There is substantial evidence that oxidative stress causes negative outcomes in many cell and tissue types. This is especially true of skeletal muscle, as it is continually subjected to various sources of reactive oxygen species (ROS). Oxidative stress in muscle has been linked to several disease states as well as to the normal aging process. Oxidative stress has also been associated with increased apoptotic signalling. Furthermore, elevated apoptosis is consistently observed in aged skeletal muscle and is thought to be one of the mechanisms of age-related muscle atrophy. Due to its post-mitotic nature, skeletal muscle may be more susceptible to the harmful effects of oxidative stress in light of its limited regenerative capacity. As a protective measure, a sophisticated antioxidant system exists in muscle consisting of both enzymatic (superoxide dismutases (SOD’s), catalase, glutathione peroxidase) and non-enzymatic elements (glutathione: GSH). GSH is a ubiquitously expressed tripeptide essential to maintenance of the redox status of the cell. Its role in skeletal muscle apoptosis, especially in different muscle types, is currently unclear. To elucidate the potential role of GSH in skeletal muscle apoptosis and oxidative stress, L-buthionine-[S,R]-sulfoximine (BSO) was used to deplete GSH in young (34.85 ± 0.68 wks) and old (69.11 ± 3.61 wks) male Sprague-Dawley rats. Thiol levels (GSH, GSSG), ROS production, 4-hydroxy-2-nonenal (4HNE) levels, DNA fragmentation and apoptosis-related protein expression were examined in soleus (SOL) and white gastrocnemius (WG) muscle. BSO led to significant GSH depletion (89% in SOL, 96% in WG) compared to age-matched controls. Catalase upregulation, in the absence of change in SOD levels, was evident as a result of BSO treatment and advancing age in both muscle tissues. BSO treatment also resulted in increased DNA fragmentation in WG and SOL, with elevated ROS production in SOL only; both of these effects were independent of age. Advancing age resulted in elevated caspase activity and Hsp70 protein content, with a concomitant decrease in anti-apoptotic ARC in SOL but not WG. Additionally, ROS production, 4HNE content, DNA fragmentation and ARC levels were all significantly elevated in SOL compared to WG. These data indicate that SOL may be subjected to a state of elevated cellular stress. There is also some evidence that GSH depletion increases DNA fragmentation while age contributes to a degradative loss of glycolytic muscle.

A power system is normally composed of a large number of generators and transmission lines that are connected through switching stations and substations. The quality and availability of power supply to the customer is highly dependent on the performance of the station equipment. Research shows that station related outages can have considerable impact on the composite system reliability. The individual station components, the station configurations and the terminal connection topologies are important factors in bulk system reliability evaluation. The major components in a station are circuit breakers, bus bars and transformers and these elements are periodically removed from service in order to conduct preventive maintenance. The removal of equipment for maintenance creates a change in the station configuration and a more vulnerable system. The failure of a related major component during a station preventive maintenance outage can result in a system disturbance and customer load loss. The bulk of the existing infrastructure of most electric power systems has been installed over the last 30 to 50 years. Aging failures of system components are a growing issue in modern electric power systems. Station related preventive maintenance outages and aging failures are important factors that affect the system reliability. This thesis examines the reliability implications of station related outages, including maintenance outages and aging outages in basic station configurations using two practical test systems. Models and techniques are created to incorporate these outages in composite system reliability evaluation. The techniques presented and the quantitative analyses illustrated in this thesis provide valuable information for a wide range of system planning, design, reinforcement and maintenance applications, including design and modification of power stations and station maintenance planning.

Decline in fertility with age has been well documented in women. There are ethical limitations to use humans as a model for basic research, and there is a lack of well characterized animal model. The objective was to characterize and validate a bovine model for the study of age-associated subfertility. All experiments were conducted on the same group of 13-14 year old cows (n=10), and their 1-4 year old young daughters (n=10). Mother-daughter pairs were used to reduce genetic variations. <p>Follicular wave pattern in a natural reproductive cycle was maintained in old cows similar to that in daughters. We hypothesized that aging in cattle is associated with elevated circulating concentrations of FSH, and reduced concentrations of steroid hormones. As stated, circulating FSH concentrations were higher (P=0.009) during follicular waves in old than young cows. The ovulatory follicle in 2-wave cycles was smaller in old cows (P=0.04), but plasma estradiol concentrations were higher (P=0.01). Luteal phase progesterone tended to be lower in old than young cows (P=0.1). The number of 4-5 mm follicles recruited into a follicular wave was lower (P<0.05) in old cows than in their daughters.<p>The response to ovarian synchronization and superstimulatory treatments was compared between old and young cows. We hypothesized that aging in cattle is associated with decreased synchrony of an induced follicular wave after steroid treatment. Conversely, the emergence of an induced follicular wave was synchronous between age groups. The preovulatory LH surge was delayed in old compared to young cows (P=0.01), but the detected ovulation times were not different. Old cows had fewer (P<0.01) follicles equal or greater than 6 mm after superstimulation, and tended (P=0.1) to have fewer ovulations than their daughters (32±4 versus 40 ±3, respectively). The response of individual cows to successive superstimulatory treatments was correlated (r>0.8; P<0.0001). <p>The hypothesis of reduced oocyte developmental competence in old cows was tested by comparing embryo production and pregnancy rates between old and young cows. Fewer (P=0.04) embryos were recovered from old cows (6±2) than their daughters (12±2). A higher proportion (P<0.01) of unfertilized oocytes and/or uncleaved zygotes were recovered from old cows (222/312, 71%) than their daughters (119/316, 38%). The recovery of fewer embryos in old cows suggests reduced oocyte developmental competence. The survival of embryos after transfer into unrelated young recipients was similar between age groups. <p>The effects of advanced age on oocyte meiotic maturation and oocyte chromosome numbers abnormalities were studied in old and young cows. Our hypothesis of compromised oocyte meiotic maturation with age was not supported; similar or higher proportion of metaphase II oocytes were recovered from old than young cows. The abnormalities of oocyte chromosomal numbers were similar between age groups. <p>To conclude, endocrine, follicular and oocyte developmental changes in old cows are consistent with those reported for women approaching menopause. Therefore, our results validated the use of a bovine model to study age-associated subfertility in women. Unlike women, we did not detect an age-related increase in abnormalities of oocyte chromosome numbers in cattle.

With the increase in research on age-related decline in human cognitive capabilities has come an increased demand for a nonhuman cognitive aging model that controls for confounds in the human research, including education, socio-economic class, and language abilities. A nonhuman primate model of cognitive aging is particularly attractive given the similarities in physiology and behavior between nonhuman primates and humans. The rhesus macaque has proven to be a highly effective model of human aging, but apes, the closest genetic relatives to humans, are virtually unstudied. Only three studies have examined age-related changes in cognitive abilities in apes, and all three studies were conducted using tasks that have had relatively little success in revealing age-related performance decline in monkeys. Sixteen gorillas housed at Zoo Atlanta and Disneys Animal Kingdom underwent five experiments to determine the effects of age, sex, and previous research experience on performance. Testing occurred in a modified Wisconsin General Test Apparatus using the delayed response paradigm. When delay intervals were increased from zero to 90 seconds performance decreased across all subjects. However, there was no univariate effect of age, sex, or experience on performance. Similarly, when the number of potential choice sites was increased from two to four there was a decrease in performance, but again there was no univariate effect of age, sex, or experience. However, older subjects were more likely to have a response bias and choose a single site across all tasks, irrespective of where the reward was located. This effect was more pronounced in inexperienced subjects. As a result, age does not appear to affect performance accuracy in the delayed response task in gorillas, but there may be an effect on response rigidity. Given the shortcomings of the delayed response task in simple cognitive studies with nonhuman primates, further research on cognitive aging in gorillas should utilize a research naïve population and use an experimental protocol that is titrated based on individual responses. This will allow the delay interval to be gradually increased to a point where age-related differences may be apparent.

Designers and researchers have often assumed that individuals rely to some degree on individual perceptions of a product's hazard when interacting with warning systems that accompany the product. However, few investigations have been made to determine what precisely these perceptions are, and how they may differ across diverse populations (such as age). Younger and older adults were tested for perceived product hazards over a diverse group of products using a Battig and Montague (1969) style procedure. Participants were presented with a total of 78 products, and asked to list the first hazards that came to their mind (up to 7 per product) for each. Comparisons revealed age-related differences between the most commonly perceived hazards for 28 of the products, with many of the age-related differences not predicted prior to data collection. The resulting data additionally form a tool for designing warning systems and research stimuli based on the products or classes of products represented in this sample.

Abstract The global phenomenon of declining birthrate and aging society have provided promising prospects for the future development of smart robots (´¼¼z«¬¾÷¾¹¤H). In respond to this need, large amount of R&D, manufacturing and HR resources have been put in the training, technology and product development of smart robots. Not only should Taiwan accelerate the overall implementation strategy for this emerging industry, it should also understand the worldwide robotics industry development overview. This paper has organized worldwide R&D and educational implementation of smart robots for the past year along with conducting in-depth interviews with domestic experts and government agencies. These studies show different country¡¦s corresponding strategy on their own industry development, R&D personnel training, implementation into the education systems, and technology innovation applications for robotics industry. It will also analyze the necessity of promoting education on robot technology as suggested by domestic scholars and professionals. From the multiple perspective of international environment, changes in the domestic educational environment, national development objectives, to Dahan Co. Ltd strategies, we can conclude the promotion of education in robotics technology is beneficial in innovation and creativity. It is also necessary as it can help to encourage students to conduct research in this field. The purpose of this thesis is to provide a feasible proposal that creates a synergy between the developments of the robotics technology industry and also Taiwan¡¦s educational system.

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.

Glassy polymers are extensively used to make all kinds of structural components. Polymers, such as epoxies, are often chosen as matrices in polymer matrix composites (PMC). Ever since the 1960s, these types of composites have been gaining importance in aerospace and automotive advanced applications due to their high sti ness and weight saving potential. In order to provide clues on the dependence of the fracture behavior upon the stress triaxiality, a series of tensile tests on epoxy (Epon862) round notched bars were carried out at NASA Glenn Research Center. Using state-of-the-art non-contact dig- ital image correlation measurement technique, the mechanical quantities of interest were extracted in order to understand how the fracture behavior responds when sub- jected to various levels of stress triaxiality induced by varying the notch radius of the specimens. E ects of aging on the fracture behavior were also investigated. A physics-based macromolecular constitutive model that accounts for temperature and pressure sensitivity as well as small-strain softening and large-strain hardening was used to model the deformation behavior. Good correlation between experiments and numerical simulations was achieved. To predict fracture, a pressure-sensitive model motivated by previous work is introduced. Based on the experimental and numerical results, the relation between the mean strain to failure versus the stress triaxiality was de ned and it was shown that the fracture response of the material is strongly a ected by the level of stress triaxiality.

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