948 resultados para accelerated aging


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We study numerically the out-of-equilibrium dynamics of the hypercubic cell spin glass in high dimensionalities. We obtain evidence of aging effects qualitatively similar both to experiments and to simulations of low-dimensional models. This suggests that the Sherrington-Kirkpatrick model as well as other mean-field finite connectivity lattices can be used to study these effects analytically.

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Report on the Iowa Department on Aging for the year ended June 30, 2011

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ABSTRACT : Genetic approach in the sleep field is at the beginning of its wide expansion. Transitions between sleep and wakefulness, and the maintenance of these states are driven by complex neurobiologic mechanisms with reciprocal interactions. Impairment in both transitions and maintenance of behavioral states leads to debilitating conditions. The major symptom being excessive daytime sleepiness, characterizing most sleep disorders but also a wide variety of psychiatric and neurologic disorders, as well as the elderly. Until now, most wake-promoting drugs available directly (e.g., amphetamines and possibly modafinil) or indirectly (e.g., caffeine) provokes dopamine release which is believed to influence the abuse potential of these drugs. The effects of genetic components were assessed here, on drug-induced wakefulness and age-related sleep changes in three inbred mouse strains [AKR/J, C57BL/6J, DBA/2J] that differ in their major sleep phenotypes. Three wake-promoting drugs were used; d-amphetamine, a classical stimulant, modafinil, the most widely-prescribed stimulant, and YKP-10A, a novel wake-promoting agent with antidepressant proprieties. Electrical activity (Electroencephalogram) and gene expression of the brain were assessed and indicate a highly genotype-dependant response to wake promotion and subsequent recovery sleep. Aging effects on sleep-wake regulation were also strongly influenced by genetic determinants. By assessing the age-dependant effects at several time points (from 3 months to 2 years old mice), we found a strong genetic effect on vigilance states. These studies demonstrate a critical role for genetic factors neglected till now in the fields of pharmacology and aging effects on vigilance states.

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In July 2006, construction began on an accelerated bridge project in Boone County, Iowa that was composed of precast substructure elements and an innovative, precast deck panel system. The superstructure system consisted of full-depth deck panels that were prestressed in the transverse direction, and after installation on the prestressed concrete girders, post-tensioned in the longitudinal direction. Prior to construction, laboratory tests were completed on the precast abutment and pier cap elements. The substructure testing was to determine the punching shear strength of the elements. Post-tensioning testing and verification of the precast deck system was performed in the field. The forces in the tendons provided by the contractor were verified and losses due to the post-tensioning operation were measured. The stress (strain) distribution in the deck panels due to the post-tensioning was also measured and analyzed. The entire construction process for this bridge system was documented. Representatives from the Boone County Engineers Office, the prime contractor, precast fabricator, and researchers from Iowa State University provided feedback and suggestions for improving the constructability of this design.

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The importance of rapid construction technologies has been recognized by the Federal Highway Administration (FHWA) and the Iowa DOT Office of Bridges and Structures. Recognizing this a two-lane single-span precast box girder bridge was constructed in 2007 over a stream. The bridge’s precast elements included precast cap beams and precast box girders. Precast element fabrication and bridge construction were observed, two precast box girders were tested in the laboratory, and the completed bridge was field tested in 2007 and 2008.

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The importance of rapid construction technologies has been recognized by the Federal Highway Administration (FHWA) and the Iowa DOT Office of Bridges and Structures. Black Hawk County (BHC) has developed a precast modified beam-in-slab bridge (PMBISB) system for use with accelerated construction. A typical PMBISB is comprised of five to six precast MBISB panels and is used on low volume roads, on short spans, and is installed and fabricated by county forces. Precast abutment caps and a precast abutment backwall were also developed by BHC for use with the PMBISB. The objective of the research was to gain knowledge of the global behavior of the bridge system in the field, to quantify the strength and behavior of the individual precast components, and to develop a more time efficient panel-to-panel field connection. Precast components tested in the laboratory include two precast abutment caps, three different types of deck panel connections, and a precast abutment backwall. The abutment caps and backwall were tested for behavior and strength. The three panel-to-panel connections were tested in the lab for strength and were evaluated based on cost and constructability. Two PMBISB were tested in the field to determine stresses, lateral distribution characteristics, and overall global behavior.

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The need to construct bridges that last longer, are less expensive, and take less time to build has increased. The importance of accelerated bridge construction (ABC) technologies has been realized by the Federal Highway Administration (FHWA) and the Iowa Department of Transportation (DOT) Office of Bridges and Structures. This project is another in a series of ABC bridge projects undertaken by the Iowa DOT. Buena Vista County, Iowa, with the assistance of the Iowa Department of Transportation (DOT) and the Bridge Engineering Center (BEC) at Iowa State University, constructed a two-lane single-span precast box girder bridge, using rapid construction techniques. The design involved the use of precast, pretensioned components for the bridge superstructure, substructure, and backwalls. This application and demonstration represents an important step in the development and advancement of these techniques in Iowa as well as nationwide. Prior funding for the design and construction of this bridge (including materials) was obtained through the FHWA Innovative Bridge Research and Deployment (IBRD) Program. The Iowa Highway Research Board (IHRB) provided additional funding to test and evaluate the bridge. This project directly addresses the IBRD goal of demonstrating (and documenting) the effectiveness of innovative materials and construction techniques for the construction of new bridge structures. Evaluation of performance was formulated through comparisons with design assumptions and recognized codes and standards including American Association of State Highway and Transportation Officials (AASHTO) specifications.

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The reintroduction of the Iowa Department on Aging legislative and policy update, now known as “Aging Watch.” The Department is providing this update to better inform you about policy affecting older Iowans. In addition to policy updates from the statehouse and the nation’s capitol, you’ll learn about Department programs and changes affecting the landscape. As you’ll learn reading this and future editions, big changes are coming for the Iowa Aging Network. Over the next year the Department will be reducing the number of local Area Agencies on Aging, as required by legislative action. Not surprisingly, this is a major change for everyone.

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The reintroduction of the Iowa Department on Aging legislative and policy update, now known as “Aging Watch.” The Department is providing this update to better inform you about policy affecting older Iowans. In addition to policy updates from the statehouse and the nation’s capitol, you’ll learn about Department programs and changes affecting the landscape. As you’ll learn reading this and future editions, big changes are coming for the Iowa Aging Network. Over the next year the Department will be reducing the number of local Area Agencies on Aging, as required by legislative action. Not surprisingly, this is a major change for everyone.

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The reintroduction of the Iowa Department on Aging legislative and policy update, now known as “Aging Watch.” The Department is providing this update to better inform you about policy affecting older Iowans. In addition to policy updates from the statehouse and the nation’s capitol, you’ll learn about Department programs and changes affecting the landscape. As you’ll learn reading this and future editions, big changes are coming for the Iowa Aging Network. Over the next year the Department will be reducing the number of local Area Agencies on Aging, as required by legislative action. Not surprisingly, this is a major change for everyone.

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The reintroduction of the Iowa Department on Aging legislative and policy update, now known as “Aging Watch.” The Department is providing this update to better inform you about policy affecting older Iowans. In addition to policy updates from the statehouse and the nation’s capitol, you’ll learn about Department programs and changes affecting the landscape. As you’ll learn reading this and future editions, big changes are coming for the Iowa Aging Network. Over the next year the Department will be reducing the number of local Area Agencies on Aging, as required by legislative action. Not surprisingly, this is a major change for everyone.

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The reintroduction of the Iowa Department on Aging legislative and policy update, now known as “Aging Watch.” The Department is providing this update to better inform you about policy affecting older Iowans. In addition to policy updates from the statehouse and the nation’s capitol, you’ll learn about Department programs and changes affecting the landscape. As you’ll learn reading this and future editions, big changes are coming for the Iowa Aging Network. Over the next year the Department will be reducing the number of local Area Agencies on Aging, as required by legislative action. Not surprisingly, this is a major change for everyone.

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The reintroduction of the Iowa Department on Aging legislative and policy update, now known as “Aging Watch.” The Department is providing this update to better inform you about policy affecting older Iowans. In addition to policy updates from the statehouse and the nation’s capitol, you’ll learn about Department programs and changes affecting the landscape. As you’ll learn reading this and future editions, big changes are coming for the Iowa Aging Network. Over the next year the Department will be reducing the number of local Area Agencies on Aging, as required by legislative action. Not surprisingly, this is a major change for everyone.

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The reintroduction of the Iowa Department on Aging legislative and policy update, now known as “Aging Watch.” The Department is providing this update to better inform you about policy affecting older Iowans. In addition to policy updates from the statehouse and the nation’s capitol, you’ll learn about Department programs and changes affecting the landscape. As you’ll learn reading this and future editions, big changes are coming for the Iowa Aging Network. Over the next year the Department will be reducing the number of local Area Agencies on Aging, as required by legislative action. Not surprisingly, this is a major change for everyone.

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The PAR-domain basic leucine zipper (PAR bZip) transcription factors DBP, TEF, and HLF accumulate in a highly circadian manner in several peripheral tissues, including liver and kidney. Mice devoid of all three of these proteins are born at expected Mendelian ratios, but are epilepsy prone, age at an accelerated rate, and die prematurely. In the hope of identifying PAR bZip target genes whose altered expression might contribute to the high morbidity and mortality of PAR bZip triple knockout mice, we compared the liver and kidney transcriptomes of these animals to those of wild-type or heterozygous mutant mice. These experiments revealed that PAR bZip proteins control the expression of many enzymes and regulators involved in detoxification and drug metabolism, such as cytochrome P450 enzymes, carboxylesterases, and constitutive androstane receptor (CAR). Indeed, PAR bZip triple knockout mice are hypersensitive to xenobiotic compounds, and the deficiency in detoxification may contribute to their early aging.