6,629 research outputs found
Short term effects of irradiance on the growth of Pterocladiella capillacea (Gelidiales, Rhodophyta)
Pterocladiella capillacea has been economically exploited for agar extraction in the Azores for many years. Harvesting dropped to a full stop in the early 1990s due to a population collapse, but restarted in 2013. Since then it has been intensively harvested and overexploitation must be prevented, with both sustainable harvesting and effective cultivation practices. This study represents the first attempt to determine optimal conditions for P. capillacea production in the Azores, and evaluates its vegetative growth in two experiments using von Stosch’s medium designed to test entire thallus and tips portions response to different irradiances (30, 70 and 150 μmol photons m¯² s¯¹). The best relative growth rate (RGR) was recorded at 150 μmol photons m¯² s¯¹ for the entire thalli and tips after two-weeks and three-weeks, respectively, indicating that an acclimation period is necessary to assure the growth of this alga under experimental conditions. Higher RGR was obtained at higher irradiance (3.98 ± 2.10% fm day¯¹), but overall, growth rates were low or negative. Epiphytes were a serious problem towards the end of the entire thallus experiments, where Feldmannia irregularis proliferate at all irradiances. Future cultivation approaches complemented with other relevant environmental factors (e.g. pH, photoperiod, salinity), are recommended.FCT – Fundação para a Ciência e Tecnologia projects UID/BIA/00329/2013, 2015 - 2018 and UID/BIA/00329/2019, CIRN (Centro de Investigação de Recursos Naturais, University of the Azores), and CIIMAR (Interdisciplinary Centre of Marine and Environmental Research, Porto, Portugal). RFP was supported by a doctoral grant M3.1.2/F/024/2011, Fundo Regional para a Ciência e Tecnologia.info:eu-repo/semantics/publishedVersio
"Automobiles: Strategy-based Lean Production System"
The present situations and future prospects of the Japanese automobile industry are discussed. Selected topics in this paper include the following: analyses of the basic product-industry characteristics of the automobile (e.g., product architecture); the mature of the dynamic competition in the world auto industry; competitive performance (e.g., productivity) of the Japanese auto makers; organizational capabilities of better Japanese firms in production, development and procurement; overall environments in the 1990s; the concept of "balanced lean" system and its adaptation to environmental changes; new flexible production systems that cope with volume fluctuation; architectural strategies of the auto firms; modularization of parts; M&A and alliance; future of the automobile technologies and architectures; future of the capability-building competition.
Broadband waveguided light sources
In recent years, broadband fiber interferometers have become very popular as basic instruments used in optical low-coherence reflectometry for diagnostics of fiber and integrated optics devices or in optical coherence tomography (OCT) for imaging applications in the biomedical field. The longitudinal resolution of such instruments is inversely proportional to the optical bandwidth of the light source. Broadband luminescence from transition-metal-ion or rare-earth-ion doped materials can significantly improve the longitudinal resolution compared to superluminescent diodes, but the low brightness of its luminescence typically leads to a low dynamic range in OCT. Femtosecond lasers based on, e.g., Ti:sapphire have, therefore, been used as large-bandwidth high-brightness light sources, and subcellular imaging has been demonstrated in this way. Since current femtosecond light sources do not necessarily meet the requirements of compactness, ease of use, and low cost, a suitable light source for OCT is still not available.\ud
We have demonstrated the suitability of a superluminescent Ti:sapphire crystal as a light source in the wavelength region 700-1000 nm for OCT. Single spatial mode, fiber coupled output powers of ~40 µW can be generated using a 5 W pump, and OCT with ~2 µm axial resolution has been performed [1]. Guiding of the fluorescence in planar-waveguide geometry can further increase the single-mode fluorescence output powers [2]. Ultimately, in a channel-waveguide geometry, the coupling efficiency of fluorescence emission into a single-mode fiber is expected to further increase to the mW level. The significantly improved sensitivity that will result at this fluorescence power may allow for rapid in vivo ultrahigh-resolution OCT with a simple broadband light source.\ud
We have successfully created Ti:sapphire channel waveguides by rib fabrication in pulsed-laser-deposition grown Ti:sapphire planar waveguides by reactive ion etching [3] or Ar+ beam milling [4] through polyimide contact masks. We are also currently investigating ion beam implantation as a tool for producing sapphire and Ti:sapphire planar waveguides directly from bulk material [5].\ud
Comparison of the output characteristics between transition-metal-ion and rare-earth-ion doped waveguide structures and its consequences for interferometry will be given at the conference.\ud
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[1] A.M. Kowalevicz, T. Ko, I. Hartl, J.G. Fujimoto, M. Pollnau, R.P. Salathé, Opt. Express 10, 349 (2002).\ud
[2] M. Pollnau, R.P. Salathé, T. Bhutta, D.P. Shepherd, R.W. Eason, Opt. Lett. 26, 283 (2001).\ud
[3] A. Crunteanu, M. Pollnau, G. Jänchen, C. Hibert, P. Hoffmann, R.P. Salathé, R.W. Eason, C. Grivas, D.P. Shepherd, Appl. Phys. B 75, 15 (2002).\ud
[4] C. Grivas, D.P. Shepherd, T.C. May-Smith, R.W. Eason, M. Pollnau, A. Crunteanu, M. Jelinek, IEEE J. Quantum Electron. 39, 501 (2003).\ud
[5] L. Laversenne, A. Crunteanu, P. Hoffmann, M. Pollnau, P. Moretti, J. Mugnier, in Conference on Lasers and Electro-Optics Europe, Munich, Germany, 2003, paper CG3-2-WED, accepted
The Egg Nebula (AFGL 2688): Deepening Enigma
Recent observations of the Egg Nebula (AFGL 2688), obtained at
ever-increasing spatial and spectral resolution, have revealed a perplexing
array of phenomena. Many of these phenomena present challenges to our
understanding of this object as an emerging, bipolar planetary nebula. Here, we
consider two particularly intriguing aspects of the Egg: the peculiar structure
and kinematics of its equatorial regions, and the nature of an apparent widely
separated companion to the central star. In the first case, we use recently
acquired Hubble Space Telescope images to demonstrate that the H2 emission
distributed east and west of the central star is spatially coincident with a
dusty, equatorial disk or torus. The H2 is thus constrained to lie near the
equatorial plane, casting doubt on pure radial outflow models for the
equatorial kinematics. In the second case, we show that the apparent companion
(``Peak A'') may be an accreting white dwarf that has undergone one or more
thermonuclear bursts.Comment: 4 pages, 1 figure; to appear in "Asymmetrical Planetary Nebulae III"
editors M. Meixner, J. Kastner, N. Soker, & B. Balick (ASP Conf. Series
Interview with Bunji Fujimoto
The son of an independent sugarcane grower remembers family life, cane cutting work, and schooling. A Laupahoehoe School student, he describes the receding ocean and the tidal wave that claimed the lives of fellow students, including his younger brother, and teachers on April 1, 1946.sugar plantation field worker, agriculture laboratory worker; Japanese; maleInterview conducted in English.State, Communit
Commodity Content in a General Input-Output Model: A Comment
This paper critically analyses the approach to the determination of values, or commodity contents, developed by Fujimoto and Opocher (2009). Even setting aside various problematic definitional issues, the broader implications of the approach for classical theory are unclear. First, the value-theoretic definitions of skill differentials and bads capture at best necessary conditions and it is unlikely that such definitions can be provided by focusing only on the technological data of the economy. Second, the approach has various interesting implications concerning the relation between productivity and exploitation that directly contradict some of the authors' claims.Value, Bads, Skilled and Unskilled Labour, Productivity and Exploitation
Kikuchi — Fujimoto disease: cervical lymphadenopathy suggestive of relapsing lymphoma in patient with lymphoblastic lymphoma
Aim: Kikuchi — Fujimoto disease (KFD) or histiocytic necrotizing lymphadenitis is a rare disorder and often confused with lymphoma. Patient: There is presented a case of 28-year-old patient with cervical lymphadenopathy, who had history of lymphoma. Results: On immunohistopathologic examination diagnosis of KFD was made and patient followed without any treatment. Conclusion: Patient’s lymphadenopathy had almost resolved and he was completely asymptomatic after three months. In patient with cervical lymphadenopathy KFD should be considered in the differential diagnosis
A Note on Duality in Inequality Systems
The purpose of this note is to present a proposition on a sort of duality relation concerning systems of nonlinear inequalities. A useful theorem due to A.W. Tucker(1956) on duality relations valid for systems of linear inequalities was partially generalized to systems of nonlinear inequalities in Fujimoto(1980), in which a given vector-valued mapping is assumed to be either pseudoconcave or homogeneous of a positive degree. Another partial extension of Tucker's result is made in Fujimoto-Ranade(1995), where the concavity of a given mapping is required. The assumption of concavity seems too strong in a model with externalities and variable returns, and so in this note a weaker assumption of pseudoconcavity is restored with an additional requirement
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