1,279 research outputs found
Physiological influences can outweigh environmental signals in otolith microchemistry research
No full textMost studies that infer geographic distributions of fish using otolith microchemistry assume that environmental factors (e.g. temperature, salinity) outweigh intrinsic effects (e.g. size, condition); however, this assumption has not been rigorously tested, particularly in marine fish. Here, we report the results of a long-term experimental study of European plaice Pleuronectes platessa L. and explore relationships between blood plasma and ambient water chemistry over a 12 mo reproductive cycle. Overall, blood plasma was found to be highly regulated, with few elements exhibiting strong, if any, correlation with ambient concentrations. This sets a first order limit on the sensitivity of otolith chemistry to fluctuations in ambient seawater chemistry. The observed temporal, ontogenetic and sex-specific variations in blood plasma elemental concentrations indicated significant physiological influences on elemental uptake and processing mechanisms. Physiological variables exerted relatively strong influences on the uptake and regulation of the softer, more thiophilic elements (Mn, Cu, Zn, Se and Pb), as well as Sr and Ca. By contrast, seasonal and sex-related variations were relatively minor among the hard acid metal ions (Li+, Mg2+, K+, Rb+, Ba2+). Overall, plasma elemental concentrations covaried most strongly and consistently with plasma protein concentrations. For this exclusively marine species, seasonal changes in physiology governed intra-annual variations in blood chemistry and, by implication, also regulate ion availability to the otolith. Based on these observations, we recommend that sex and age should be controlled for in future experimental designs using otolith microchemistry to infer stock structure or migration patterns
Quantifying physiological influences on otolith microchemistry
No full textSummary Trace element concentrations in fish earstones (‘otoliths’) are widely used to discriminate spatially discrete populations or individuals of marine fish, based on a commonly held assumption that physiological influences on otolith composition are minor, and thus variations in otolith elemental chemistry primarily reflect changes in ambient water chemistry. We carried out a long-term (1-year) experiment, serially sampling seawater, blood plasma and otoliths of mature and immature European plaice (Pleuronectes platessa L.) to test relationships between otolith chemistry and environmental and physiological variables. Seasonal variations in otolith elemental composition did not track seawater concentrations, but instead reflected physiological controls on metal transport and biokinetics, which are likely moderated by ambient temperature. The influence of physiological factors on otolith composition was particularly evident in Sr/Ca ratios, the most widely used elemental marker in applied otolith microchemistry studies. Reproduction also triggered specific variations in otolith and blood plasma metal chemistry, especially Zn/Ca ratios in female fish, which could potentially serve as retrospective spawning indicators. The influence of physiology on the trace metal composition of otoliths may explain the success of microchemical stock discrimination in relatively homogenous marine environments, but could complicate alternative uses for trace element compositions in biominerals of higher organisms
Data from: Quantifying physiological influences on otolith microchemistry
No full text1. Trace element concentrations in fish earstones (“otoliths”) are widely used to discriminate spatially discrete populations or individuals of marine fish, based on a commonly held assumption that physiological influences on otolith composition are minor, and thus variations in otolith elemental chemistry primarily reflect changes in ambient water chemistry. 2. We carried out a long-term (1-yr) experiment, serially sampling seawater, blood plasma and otoliths of mature and immature European plaice (Pleuronectes platessa L.) to test relationships between otolith chemistry and environmental or physiological variables. 3. Seasonal variations in otolith elemental composition did not track seawater concentrations, but instead reflected physiological controls on metal transport and biokinetics, which are likely moderated by ambient temperature. The influence of physiological factors on otolith composition was particularly evident in Sr/Ca ratios, the most widely used elemental marker in applied otolith microchemistry studies. Reproduction also triggered specific variations in otolith and blood plasma metal chemistry, especially Zn/Ca ratios in female fish, which could potentially serve as retrospective spawning indicators. 4. The influence of physiology on the trace metal composition of otoliths may explain the success of microchemical stock discrimination in relatively chemically homogenous marine environments, but could complicate alternative uses for trace element compositions in biominerals of higher organisms.,Time series elemental and physiological data for experimental plaice serially sampled for 7-12 monthsPlaice were serially sampled for 7-12 months under ambient but monitored conditions. Each fish was sampled approximately monthly. Measurements in the attached data file include physiological variables (e.g. plasma protein concentrations, age, weight, length, female gonadosomatic index), otolith growth rates and opacity, and blood plasma and otolith elemental concentrations. Environmental data (salinity, temperature and seawater elemental concentrations) are also displayed. Note that elemental concentrations and element/calcium ratios are denoted as X.El and X.El.Ca for concentrations of element (‘El’) in medium ‘X’, where ‘X’ is either seawater (SW), blood plasma (B) or otolith (O).OTODATA_for_Dryad.xlsx</span
Orbit design for future SpaceChip swarm missions in a planetary atmosphere
No full textThe effect of solar radiation pressure and atmospheric drag on the orbital dynamics of satellites-on-a-chip (SpaceChips) is exploited to design equatorial long-lived orbits about the oblate Earth. The orbit energy gain due to asymmetric solar radiation pressure, considering the Earth's shadow, is used to balance the energy loss due to atmospheric drag. Future missions for a swarm of SpaceChips are proposed, where a number of small devices are released from a conventional spacecraft to perform spatially distributed measurements of the conditions in the ionosphere and exosphere. It is shown that the orbit lifetime can be extended and indeed selected through solar radiation pressure and the end-of-life re-entry of the swarm can be ensured, by exploiting atmospheric drag
Public Policy in a Private Arena: The Case of Vocational Education and Training
No full textM.21586-1998 Colin Crouch. 30 cm. This paper is based on a seminar that he presented at the Center for Advanced Study in the Social Sciences of the Juan March Institute, Madrid, on 9 May 1995, entitled Diversity in Modern Capitalism: Examples from Vocational Education." -- T.p. Includes bibliographical references (p. 35-37
Golden Age Jesuit: Juan Eusebio Nieremberg and the rhetoric of discernment in seventeenth-century Spain
No full textThis thesis examines the Jesuit and Ignatian influence on the works of Juan Eusebio Nieremberg (1595-1658), who was a prolific and widely published author and a member of the Society of Jesus in Spain. He wrote several works across different literary genres both in Spanish and Latin, but was best known for his popular works in Spanish: two miscellanies of natural philosophy, Curiosa filosofía (1630) and Oculta filosofía (1633); a catechism, the Práctica del catecismo romano (1640); his ascetical treatises, especially De la diferencia entre lo temporal y eterno (1640); and his ‘advice-books’ to princes and nobles, most notably Causa y remedio de los males públicos (1642). As a member of the Jesuit Order, Nieremberg wrote these works with the intention to ‘save souls’, this being the main apostolic goal of the Society. While they provide people with knowledge (‘noticia’) – whether doctrinal, natural, spiritual, or political – these works teach readers to view human existence according to its true end: God’s will of salvation. All things of the temporal world are portrayed as a means to that end. In order to accomplish this goal, Nieremberg incorporates elements from Loyola’s Ejercicios espirituales (1548), the spiritual foundation of the Jesuit Order, and develops a rhetorical strategy which encourages readers to discern the will of God in the world they inhabit. He also develops this rhetoric according to some of the principal literary and artistic conventions of the seventeenth century, and provides an important example of how a prominent Jesuit writer came to express the apostolic and spiritual principles of his Order, but in the language and imagery of Spain’s Siglo de Oro
White empty Earth: photography and the imagined world
No full textMy use of photography is rooted in the complexities of the photograph, its making, meaning and function. Human understanding and perception of the physical world (as Landscape and Nature) are sole concerns as I address the ambivalence that coincides with these ideas and the space in between. Can one achieve a work that illuminates both personally and collectively, privately and socially? By photographing constructed environments in the studio, can I challenge the photograph as "document" and the environment as fundamentally separate from human? With this work, I am hoping to accomplish several things through a hermeneutic based exploration: An engagement in a meditative, slow process, the revealing of a mindful, personal space,a deeper understanding of the environment and my place in it and the capability, functionality, conscious/unconscious uses of and meaning in photography and the photograph and, lastly, how the image affects human consciousness of and relationship to the physical world.M.F.A.Includes bibliographical references (p. 65)by Colin Jon Edgingto
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No full textThe productivity effects of decentralized reforms - an analysis of the Chinese industrial reforms
No full textThe empirical literature on the effects of ownership has not distinguished between the effects of ownership and the effects of control. It has also generally ignored the dynamic effects of various ownership and control rights. Using a rich set of panel data about changes in China's state-owned enterprises, the author examines the static and dynamic effects of decentralizing ownership and control rights. He finds that productivity and growth rates improved significantly when reform improved the incentives for managers and employees to learn and to work hard - for example by decentralizing the rights to control wages, make production decisions, and appoint new managers. Increasing profit-retention rates and adopting performance contracts - conventionally viewed as the most important reforms for China's state enterprises - did not improve productivity much. Overall, decentralization accounted for a least 42 percent of productivity growth in Chinese state enterprises in the 1980s. Much of that gain came from improvements in the growth rate of productivity rather than in improved levels of productivity.Labor Policies,Economic Theory&Research,Environmental Economics&Policies,Banks&Banking Reform,Public Health Promotion,Economic Theory&Research,Environmental Economics&Policies,Banks&Banking Reform,Health Monitoring&Evaluation,Municipal Financial Management
Oregon statewide status and trends report
No full textReport -- Appendix A. Black Rock Desert-Humboldt -- Appendix B. Columbia River -- Appendix C. Deschutes -- Appendix D. Goose Lake -- Appendix E. Grande Ronde -- Appendix F. John Day -- Appendix G. Klamath -- Appendix H. Malheur -- Appendix I. Mid Coast -- Appendix J. Middle-Columbia-Hood -- Appendix K. North Coast-Lower Columbia -- Appendix L. Oregon Closed Basins -- Appendix M. Owyhee -- Appendix N. Powder-Burnt -- Appendix O. Rogue -- Appendix P. Sandy -- Appendix Q. Snake River -- Appendix R. South Coast -- Appendix S. Umatilla-Walla Walla-Willow -- Appendix T. Umpqua -- Appendix U. Willamette.prepared by: Colin Donald and Ryan Michie.Title from PDF cover (viewed on November 4, 2022).This archived document is maintained by the State Library of Oregon as part of the Oregon Documents Depository Program. It is for informational purposes and may not be suitable for legal purposes.Includes bibliographical references.Mode of access: Internet from the Oregon Government Publications Collection.Text in English
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