3 resultados para Loss Determination in Microsphere Resonators
em Bucknell University Digital Commons - Pensilvania - USA
Resumo:
The examination of telomere dynamics is a recent technique in ecology for assessing physiological state and age-related traits from individuals of unknown age. Telomeres shorten with age in most species and are expected to reflect physiological state, reproductive investment, and chronological age. Loss of telomere length is used as an indicator of biological aging, as this detrimental deterioration is associated with lowered survival. Lifespan dimorphism and more rapid senescence in the larger, shorter-lived sex are predicted in species with sexual size dimorphism, however, little is known about the effects of behavioral dimorphism on senescence and life history traits in species with sexual monomorphism. Here we compare telomere dynamics of thick-billed murres (Uria lomvia), a species with male-biased parental care, in two ways: 1) cross-sectionally in birds of known-age (0-28 years) from one colony and 2) longitudinally in birds from four colonies. Telomere dynamics are compared using three measures: the telomere restriction fragment (TRF), a lower window of TRF (TOE), and qPCR. All showed age-related shortening of telomeres, but the TRF measure also indicated that adult female murres have shorter telomere length than adult males, consistent with sex-specific patterns of ageing. Adult males had longer telomeres than adult females on all colonies examined, but chick telomere length did not differ by sex. Additionally, inter-annual telomere changes may be related to environmental conditions; birds from a potentially low quality colony lost telomeres, while those at more hospitable colonies maintained telomere length. We conclude that sex-specific patterns of telomere loss exist in the sexually monomorphic thick-billed murre but are likely to occur between fledging and recruitment. Longer telomeres in males may be related to their homogamous sex chromosomes (ZZ) or to selection for longer life in the care-giving sex. Environmental conditions appeared to be the primary drivers of annual changes in adult birds.
Resumo:
Solar energy is the most abundant persistent energy resource. It is also an intermittent one available for only a fraction of each day while the demand for electric power never ceases. To produce a significant amount of power at the utility scale, electricity generated from solar energy must be dispatchable and able to be supplied in response to variations in demand. This requires energy storage that serves to decouple the intermittent solar resource from the load and enables around-the-clock power production from solar energy. Practically, solar energy storage technologies must be efficient as any energy loss results in an increase in the amount of required collection hardware, the largest cost in a solar electric power system. Storing solar energy as heat has been shown to be an efficient, scalable, and relatively low-cost approach to providing dispatchable solar electricity. Concentrating solar power systems that include thermal energy storage (TES) use mirrors to focus sunlight onto a heat exchanger where it is converted to thermal energy that is carried away by a heat transfer fluid and used to drive a conventional thermal power cycle (e.g., steam power plant), or stored for later use. Several approaches to TES have been developed and can generally be categorized as either thermophysical (wherein energy is stored in a hot fluid or solid medium or by causing a phase change that can later be reversed to release heat) or thermochemical (in which energy is stored in chemical bonds requiring two or more reversible chemical reactions).
Resumo:
While it is only in recent decades that scholars have begun to reconsider and problematize Buddhist conceptions of “freedom” and “agency,” the thought traditions of Asian Buddhism have for many centuries struggled with questions related to the issue of “liberation”—along with its fundamental ontological, epistemological and ethical implications. With the development of Marxist thought in the mid to late nineteenth century, a new paradigm for thinking about freedom in relation to history, identity and social change found its way to Asia, and confronted traditional religious interpretations of freedom as well as competing Western ones. In the past century, several attempts have been made—in India, southeast Asia, China and Japan—to bring together Marxist and Buddhist worldviews, with only moderate success (both at the level of theory and practice). This paper analyzes both the possibilities and problems of a “Buddhist materialism” constructed along Marxian lines, by focusing in particular on Buddhist and Marxist conceptions of “liberation.” By utilizing the theoretical work of Japanese “radical Buddhist” Seno’o Girō, I argue that the root of the tension lies with conceptions of selfhood and agency—but that, contrary to expectations, a strong case can be made for convergence between Buddhist and Marxian perspectives on these issues, as both traditions ultimately seek a resolution of existential determination in response to alienation. Along the way, I discuss the work of Marx, Engels, Gramsci, Lukàcs, Sartre, and Richard Rorty in relation to aspects of traditional (particularly East Asian Mahāyāna) Buddhist thought.