| 1. |
- Andre, C., et al.
(författare)
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Predation on Settling Bivalve Larvae by Benthic Suspension Feeders - the Role of Hydrodynamics and Larval Behavior
- 1993
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Ingår i: Marine Ecology-Progress Series. - 0171-8630. ; 97:2, s. 183-192
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Tidskriftsartikel (refereegranskat)abstract
- Predation by the suspension-feeding infaunal bivalve Cerastoderma edule on settling C. edule larvae was studied in a flume boundary-layer flow. The density of settled larvae was reduced by 33% in an area of 5 cm2 enclosing individual adults. Mean survival time for competent C. edule larvae drifting over sediment populated with feeding adults (380 ind. m-2) was 64 s, and 75% of the observed larvae were inhaled by adults. Observations of the siphonal currents produced by C. edule and the swimming behaviour of larvae were combined in a computer model to assess the importance of adult density and boundary-layer flow on the predation risk experienced by settling larvae. Survival of settling larvae decreased drastically with increasing adult density, whereas increased flow velocity caused only a slightly higher predation risk. Although reduction in larval settlement on the scale of individual adults may be small or moderate, inhalation of settling larvae by populations of resident suspension feeders may cause a significant decrease in settlement on a larger scale (10(1) to 10(3) m).
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| 2. |
- Carlsson, Christina, 1968, et al.
(författare)
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OPTICAL AND PHOTOPHYSICAL PROPERTIES OF THE OXAZOLE YELLOW DNA PROBES YO AND YOYO
- 1994
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Ingår i: Journal of Physical Chemistry. - : American Chemical Society (ACS). - 0022-3654 .- 1541-5740. ; 98:40, s. 10313-10321
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Tidskriftsartikel (refereegranskat)abstract
- The photophysical properties of the optical DNA probe YOYO (homodimeric derivative of oxazole yellow) have been characterized in terms of the monomeric part, the YO chromophore. In aqueous solutions YO is virtually nonfluorescent but upon binding to DNA its fluorescence quantum yield is strongly increased. A similar enhancement of the fluorescence is observed for YO in the viscous solvent glycerol. The high fluorescence quantum yield of YO, when bound to DNA or in a viscous solution, is proposed to be a result of decreased rotational mobility around the internuclear bridge between the two aromatic ring systems. This hypothesis is based on similar values of the activation energies for the temperature-dependent nonradiative decay processes (E(A) = 53 kJ/mol) and viscous flow (E(A) = 63 kJ/mol), suggesting related rate-limiting mechanisms. A single electronic transition is found to be responsible for the intense visible absorption band. This conclusion is based on the observation of an essentially wavelength-independent reduced linear dichroism and similarly wavelength independent fluorescence anisotropy, and the fact that the emission spectrum is very nearly a mirror image of the absorption spectrum. The conclusion is further supported by quantum mechanical calculations (CNDO/S). By combination of measurements of fluorescence anisotropy of YO in glycerol and linear dichroism of YO in a stretched poly(vinyl alcohol) film, the transition moment of the strong visible absorption band was found to be nearly long axis polarized, in agreement with the CNDO/S calculations. The low-energy electronic transition and its polarization direction in the YO chromophore remain essentially unperturbed in the YOYO dye, suggesting that the results obtained for the excited state of the YO chromophore are applicable also to YOYO. One difference, though, is that in aqueous solutions the two YO chromophores of YOYO interact with each other, forming an internal dimer, resulting in a distorted absorption spectrum.
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| 3. |
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| 4. |
- Ellegård, Kajsa, 1951, et al.
(författare)
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Reflective Production in the Final Assembly of Motor Vehicles - An Emerging Swedish Challenge
- 1992
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Ingår i: International Journal of Operations and Production Management. - 1758-6593 .- 0144-3577. ; 12:7/8, s. 117-133
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Tidskriftsartikel (refereegranskat)abstract
- Presents some theoretical principles and empirical evidence relating to the new Swedish production systems for final assembly of motor vehicles. Contends that in these production systems it is possible simultaneously to enhance efficiency and quality of working life. Briefly sketches three production forms as they apply to the final assembly of automobiles and discusses the societal environments in which these different forms of production have evolved. It focuses on Volvo Uddevalla plant as one of the main examples so far of a reflective production system for final assembly of automobiles. Amplifies the analysis of different production flow patterns for final assembly and in particular addresses the issue of semi‐parallel mechanistic production flow and parallel organic production flow as alternatives to serial flow on a conventional line assembly. A comment: This publication is authored together with e.g. senior research competencies (1) within vocational learning and training as well as (2) within time-geography with whom Engström have had long time cooperation procedures. But also personal at our department/research group (Mats Johansson) well as our knowledgeable contact person (Bertil Johansson) within Volvo contributed (he has really helped us out for decades and was responsible for the continuous contacts with Volvo in most any matter).
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| 5. |
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| 6. |
- Engström, Mats, et al.
(författare)
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Facial nerve enhancement in Bell's palsy demonstrated by different gadolinium-enhanced magnetic resonance imaging techniques.
- 1993
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Ingår i: Archives of Otolaryngology - Head & Neck Surgery. - 0886-4470 .- 1538-361X. ; 119:2, s. 221-225
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Tidskriftsartikel (refereegranskat)abstract
- Twenty-one patients with an acute complete peripheral facial palsy, Bell's palsy, were examined by medium- and high-Tesla magnetic resonance imaging. Three contrast techniques were used: intravenous gadolinium; oral carbohydrate and intravenous gadolinium; and gadolinium, carbohydrate, and readministration of gadolinium. Three to 22 days after the onset of palsy, 12 of the 21 patients demonstrated ipsilateral facial nerve enhancement, most consistently in the meatal region, which is indicative of an inflammatory reaction. Two to 4.5 months after the onset, the enhancement had disappeared in 10 of the 12 patients. For the individual patient, contrast-enhanced magnetic resonance imaging gave little or no help in predicting the outcome of palsy. It is speculated that the intake of carbohydrate and readministration of gadolinium may improve the sensitivity of medium-high-Tesla magnetic resonance imaging in some cases.
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| 7. |
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| 8. |
- Jonsson, Lars, et al.
(författare)
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Acute peripheral facial palsy simulating Bell's palsy in a case of probable multiple sclerosis with a clinically correlated transient pontine lesion on magnetic resonance imaging
- 1991
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Ingår i: Journal for Oto-Rhino-Laryngology. - 0301-1569 .- 1423-0275. ; 53:6, s. 362-365
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Tidskriftsartikel (refereegranskat)abstract
- A transient pontine lesion was demonstrated in a young adult male who had a complete acute peripheral facial nerve palsy due probably to multiple sclerosis. In the acute stage of the palsy. T2-weighted magnetic resonance imaging (MRI) revealed a high signal intensity in the ipsilateral pons in the region of the nucleus and pontine part of the facial nerve. The patient recovered completely 5 weeks after the onset of the palsy, and at this stage, the lesion in the brainstem was no longer demonstrable on MRI. The onset and course of the disease resembled the idiopathic form of facial palsy (Bell's palsy): the present findings along with recent MRI and topodiagnostic studies may indicate that in some cases of Bell's palsy the primary lesion is located centrally. By improved MRI techniques and intravenous contrast agents it may be possible to visualize and follow the disease process and ascertain more of the pathogenesis of Bell's palsy.
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| 9. |
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| 10. |
- Jonsson, Mikael, et al.
(författare)
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Experimentally determined deformations and stresses in narrow gap and single-U multi-pass butt-welded pipes
- 1991
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Ingår i: Proceedings of the 10th International Conference on Offshore Mechanics and Arctic Engineering, 1991. - New York : American Society of Mechanical Engineers. - 0791807193 ; , s. 17-24
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Konferensbidrag (refereegranskat)abstract
- Multi-pass butt-welding of thick walled pipes is studied. Two different groove shapes are used, single-U and narrow gap groove. Strains have been measured on both the pipe outer and inner surfaces during and after welding. Residual stresses and radial deflections have been measured on the outer surface after welding. The measured quantities are compared and discussed for the two different groove shapes. Residual stresses at the weld center and radial deflections were somewhat larger for the narrow gap groove. Furthermore, the residual stress fields for both grooves were found to be rotationally nonsymmetric. The experimentally obtained residual stresses and radial deflections are compared with corresponding analytical and empirical results based on methods from the literature and with numerical results for the same pipe from a separate study. Deviations between the measurements (on OX524D) and the results from the literature are discussed.
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