| 1. |
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| 2. |
- Alpizar, Francisco, 1974, et al.
(författare)
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How Much Do We Care About Absolute Versus Relative Income and Consumption?
- 2001
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- We find, using survey-experimental methods, that most individuals are concerned with both relative income and relative consumption of particular goods. The degree of concern varies in the expected direction depending on the properties of the good. However, contrary to what has been suggested in the previous literature, we find that relative consumption is also important for vacation and insurance, which are typically seen as non-positional goods. Further, absolute consumption is also found to be important for cars and housing, which are widely regarded as highly positional. Implications for Pareto-efficient taxation are illustrated using the results from the experiment.
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| 3. |
- Alpizar, Francisco, 1974, et al.
(författare)
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Policy Implications and Analysis of the Determinants of Travel Mode Choice: An Application of Choice Experiments to Metropolitan Costa Rica
- 2001
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- In this paper we study a group of policies aimed at discouraging the use of private transportation during peak hours, both directly and indirectly, by increasing the attractiveness of the only available substitute, the bus. This is done using a choice experiment constructed to find the answer to the following basic question: Given fixed house-to-work structures and no working hour flexibility, by how much is the choice of travel mode for commuters to work sensitive to changes in travel time, changes in costs for each mode and other service attributes? This information is then used to identify the most suitable combination of policies dealing with air pollution and congestion in the typical developing country context of metropolitan Costa Rica. We also provide estimates of the value of travel time as a measure of the potential benefits gained from reduced congestion.
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| 4. |
- Alpizar, Francisco, 1974, et al.
(författare)
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Using Choice Experiments for Non-Market Valuation
- 2003
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Ingår i: Economic Issues. ; 8, s. 83-110
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Tidskriftsartikel (refereegranskat)abstract
- This paper provides the latest research developments in the method of choice experiments applied to valuation of non-market goods. Choice experiments, along with the, by now, well-known contingent valuation method, are very important tools for valuing non-market goods and the results are used in both cost-benefit analyses and litigations related to damage assessments. The paper should provide the reader with both the means to carry out a choice experiment and to conduct a detailed critical analysis of its performance in order to give informed advice about the results. A discussion of the underlying economic model of choice experiments is incorporated, as well as a presentation of econometric models consistent with economic theory. Furthermore, a detailed discussion on the development of a choice experiment is provided, which in particular focuses on the design of the experiment and tests of validity. Finally, a discussion on different ways to calculate welfare effects is presented.
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| 5. |
- Alpizar, Francisco, 1974, et al.
(författare)
-
Using Choice Experiments for Non-Market Valuation
- 2001
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This paper provides the latest research developments in the method of choice experiments applied to valuation of non-market goods. Choice experiments, along with the, by now, well-known contingent valuation method, are very important tools for valuing non-market goods and the results are used in both cost-benefit analyses and litigations related to damage assessments. The paper should provide the reader with both the means to carry out a choice experiment and to conduct a detailed critical analysis of its performance in order to give informed advice about the results. A discussion of the underlying economic model of choice experiments is incorporated, as well as a presentation of econometric models consistent with economic theory. Furthermore, a detailed discussion on the development of a choice experiment is provided, which in particular focuses on the design of the experiment and tests of validity. Finally, a discussion on different ways to calculate welfare effects is presented.
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| 6. |
- Anghinolfi, Francisco, et al.
(författare)
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DTMROC-S: Deep submicron version of the readout chip for the TRT detector in ATLAS
- 2002
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Ingår i: 8th Workshop On Electronics For LHC Experiments. ; , s. 95-99
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Konferensbidrag (refereegranskat)abstract
- A new version of the circuit for the readout of the ATLAS straw tube detector, TRT [1], has been developed in a deep-submicron process. The DTMROC-S is fabricated in a commercial 0.25μm CMOS IBM technology, with a library hardened by layout techniques [2]. Compared to the previous version of the chip [3] done in a 0.8μm radiation-hard CMOS and despite of the features added for improving the robustness and testability of the circuit, the deep-submicron technology results in a much smaller chip size that increases the production yield and lowers the power consumption.
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| 7. |
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| 8. |
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| 9. |
- Berens, Friedbert, et al.
(författare)
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Modulation and Coding
- 2000
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Ingår i: Third Generation Mobile Communication Systems (Ramjee Prasad, Werner Mohr and Walter Konhäuser editors), chapter 5. - 1580530826
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 10. |
- Bjursäter, Ulla, et al.
(författare)
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Assessing the significance of Tallal's transform
- 2002
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Ingår i: TMH-QPSR 44: Proceedings Fonetik 2002, 141-144. - Stockholm, Sweden. ; , s. 141-144
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The perceptual significance of enhancing amplitude contrasts at the onset of formant transitions in CV-syllables and of reducing the “speaking” tempo was studied with a group of normally developing school children. Natural and synthetic speech stimuli were used in the perception experiments. A total of 83 children, second and third graders, were tested on their ability to discriminate between CV syllables presented in pairs. The results indicate that the children’s discrimination performance resisted acoustic manipulations of both the natural and synthetic stimuli. Neither spectral nor timing manipulations rendered significant differencesin discrimination results.
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| 11. |
- Bjursäter, Ulla, et al.
(författare)
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Influence of pre-school phonological training on early reading and writing abilities
- 2003
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Ingår i: 15th International Congress of Phonetic Sciences (ICPhS) 2003. ; , s. 2846-2848
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Konferensbidrag (refereegranskat)abstract
- This paper reports a study of the possible impact of pre-school phonological training on first and second graders' reading and writing abilities. Two public schools in the Stockholm metropolitan area were selected. The children were divided in two groups, depending on whether or not they had participated in a phonological training program in their last pre-school year. The children's linguistic and literacy development was followed during their first two school years. Psycholinguistic profiles (ITPA) were obtained for all the first grade children, along with an assessment of their phonological awareness. In the second grade, the children were reassessed to map their reading and writing abilities. Although the results suggested an initial advantage in general linguistic awareness for the children enrolled in the phonological training program, that advantage seems to be quickly overshadowed by social and personal factors such as continuity in the pedagogical leadership and attended school.
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| 12. |
- Bouchet, B, et al.
(författare)
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The Zambia quality assurance program: successes and challenges
- 2002
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Ingår i: International journal for quality in health care : journal of the International Society for Quality in Health Care. - : Oxford University Press (OUP). - 1353-4505. ; 1414 Suppl 1, s. 89-95
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Tidskriftsartikel (refereegranskat)
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| 13. |
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| 14. |
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| 15. |
- Carneiro, Maria Paula, et al.
(författare)
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Normas de associação livre de 16 palavras portuguesas para crianças de diferentes faixas etárias
- 2004
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Ingår i: Laboratório de Psicologia. - : ISPA - Instituto Universitario. - 1646-6004 .- 1645-7927. ; 2:1, s. 49-76
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Tidskriftsartikel (refereegranskat)abstract
- Neste estudo são apresentadas as normas de associação livre de 16 palavras portuguesas para 3 faixas etárias de crianças – 3/4 anos, 7/8 anos e 11/12 anos – e adultos. As comparações efectuadas entre as faixas etárias revelaram uma diferença significativa entre os 3/4 anos e os 7/8 anos ao nível do número de associados obtidos, provavelmente atribuída a um aumento considerável do vocabulário nesta fase do desenvolvimento. Mudanças conceptuais na organização do conhecimento foram também analisadas, verificando-se nos pré-escolares associações que revelam relações funcionais e um predomínio de relações taxonómicas a partir dos 7/8 anos.
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| 16. |
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| 17. |
- Cohen, Serge X., et al.
(författare)
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Towards complete validated models in the next generation of ARP/wARP
- 2004
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Ingår i: Acta Crystallographica Section D. - 0907-4449 .- 1399-0047. ; 60:Pt 12 Pt 1, s. 2222-9
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Tidskriftsartikel (refereegranskat)abstract
- The design of a new versatile control system that will underlie future releases of the automated model-building package ARP/wARP is presented. A sophisticated expert system is under development that will transform ARP/wARP from a very useful model-building aid to a truly automated package capable of delivering complete, well refined and validated models comparable in quality to the result of intensive manual checking, rebuilding, hypothesis testing, refinement and validation cycles of an experienced crystallographer. In addition to the presentation of this control system, recent advances, ideas and future plans for improving the current model-building algorithms, especially for completing partially built models, are presented. Furthermore, a concept for integrating validation routines into the iterative model-building process is also presented.
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| 18. |
- da Cruz Francisco, José, et al.
(författare)
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Gelatinization of cassava, potato and wheat starches in supercritical carbon dioxide
- 2002
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Ingår i: Journal of Supercritical Fluids. - 0896-8446. ; 22:3, s. 247-254
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Tidskriftsartikel (refereegranskat)abstract
- The gelatinization of cassava, potato and wheat starches in supercritical carbon dioxide was investigated using light microscope. The starch was placed in a stainless steel chamber at atmospheric pressure and high CO2 pressures, 8 and 30 MPa as well as at 8 MPa N-2 and the gelatinization degree observed by light microscopy. The results showed that both pressure and supercritical fluid affected the gelatinization degree. Cassava and potato starches showed a lowering of the gelatinization temperatures at 8 MPa and an increasing at 30 MPa as compared with the gelatinization degree at atmospheric pressure. For wheat starch, the decrease in the gelatinization temperature occurred in the same direction as the pressure increased, in comparison with the atmospheric pressure conditions. However, between the two applied pressures, there was a larger increase of the gelatinization temperature at 30 MPa than at 8 MPa. The effect of hydrostatic pressure component of the CO2 was evaluated by using N-2 at 8 MPa. The replacement of CO2 by N-2 at 8 MPa increased the gelatinization temperature for all the studied starches compared with the atmospheric conditions. (C) 2002 Elsevier Science B.V. All rights reserved.
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| 19. |
- da Cruz Francisco, José
(författare)
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On the Extraction of Essential Oils by Supercritical Carbon Dioxide and its Influence on the Mesomorphic Phase Structures
- 2002
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- A comparison of essential oils from leaves of Eucalyptus camaldulensis Dehn. obtained by hydrodistillation (HD) and supercritical carbon dioxide (SC-CO2) extraction is presented. Selected major components of the oils showed a predominance of higher molecular weight components in the SC-CO2 extracts than in those obtained by HD. Physico chemical properties such as molecular weight, vapour pressure of the components, steric factor as well as in oil composition. Discussions on environmental effects on the quality of the essential oils obtained on the same eucalyptus genotype treated by the same techniques are also presented. The monoterpenes 1,8-cineole, limonene and a-pinene, present in considerable amounts in eucalyptus leaf oils, as well as their mixtures and three eucalyptus oils from different genotypes, namely E. dives, E. polybractea and E. radiata, were also studied with regard to their solubility in dense CO2 (SC-CO2 and LCO2). In general, pure compounds showed a higher solubility in SC-CO2. The composition SC-CO2 at the highest pressure and temperature. Since polar lipids are always present in eucalyptus leaves from which the oil is extracted, the interaction between such lipids, water, SC-CO2 and essential oils is important to study. First, liquid crystalline properties and the extractability of monoolein/water systems by supercritical carbon dioxide are discussed. The most remarkable observation in this study was the loss of the native mesomorphic structure at high temperatures and the low recovery of monoolein in monoolein/water systems within the highest (18wt%) water content at temperatures between 35 and 65°C. These effects are explained by the SC-CO2, water and monoolein interactions which lead to different water and monoolein activities in the phase present. Further, two model systems composed of monoolein/water or soybean lecithin/water, cineole and SC-CO2 are presented for studying the phase behaviour. Generally, it is observed that the liquid crystalline structure remain also in presence of surplus of SC-CO2. Hence, it can be assumed that lipid structures in the plant tissues may remain also during SC-CO2 extraction and contribute to the matrix effects observed in extraction trials.
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| 20. |
- da Cruz Francisco, José, et al.
(författare)
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Phase behavior of the monoolein-water system - The effects of addition of the hydrocarbon 1,8-cineole and supercritical carbon dioxide
- 2004
-
Ingår i: Journal of Supercritical Fluids. - : Elsevier BV. - 0896-8446. ; 31:3, s. 263-271
-
Tidskriftsartikel (refereegranskat)abstract
- The results of a study on the phase behavior of the monoolein/water system with the addition of the hydrocarbon 1,8-cineole (C10H18O) and supercritical carbon dioxide at 15 MPa is presented. To two mixtures consisting of 9 and 18 wt.% water in monoolein, 5, 10, and 20 wt.% cineole were added and heated to between 35 and 80 degreesC at atmospheric pressure and in the presence of supercritical carbon dioxide. The phase changes were followed by deuterium nuclear magnetic resonance (H-2 NMR), light microscopy, and ocular inspection. The mesomorphic structures developed in the 9 wt.% water sample suffered little change due to the presence of the supercritical carbon dioxide. However, in the mixture with 18 wt.% water, the native phase structures were dramatically affected and an isotropic fluid phase developed. The addition of cineole has lowered the LC-L-alpha --> LC-H-Pi phase transition in the samples with 9 and 18 wt.% water in monoolein. The surplus of supercritical carbon dioxide in the samples has resulted in similar developments. Regardless of the amount of cineole present in the system, only the isotropic fluid phase was observed in the samples with 18 wt.% water in monoolein. (C) 2004 Elsevier B.V. All rights reserved.
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| 21. |
- da Cruz Francisco, José, et al.
(författare)
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Phase behavior of the system lecithin-water - The effects of addition of the hydrocarbon 1,8-cineole and supercritical carbon dioxide
- 2004
-
Ingår i: Journal of Supercritical Fluids. - : Elsevier BV. - 0896-8446. ; 31:3, s. 255-262
-
Tidskriftsartikel (refereegranskat)abstract
- The phase behavior of lecithin and water mixtures with addition of the hydrocarbon 1,8-cineole (C10H18O) was investigated using light microscopy and H-2 NMR at atmospheric pressure and with a surplus of supercritical carbon dioxide (15 MPa) between 35 and 80degreesC. The lecithin-water (LW) mixtures consisted of 10 and 20wt.% water in lecithin to which 5, 10, and 20wt.% cineole and supercritical carbon dioxide were added. The addition of cineole to the 10wt.% water in lecithin samples has affected the original lamellar liquid crystalline phase present and mainly transformed it into the reversed hexagonal phase at cineole concentration of 10wt.% and higher. This phase however Only Occurred when 20 wt.% cineole were added to the lecithin samples with 20wt.% water which otherwise was lamellar. The addition of supercritical carbon dioxide to the lecithin/water samples in the absence of cineole resulted in a liquid crystalline lamellar (LC-L-alpha) phase and was the same as in the original phase structure at atmospheric pressure. In the lecithin/water samples with cineole, the addition of supercritical carbon had little effect on the structure. (C) 2004 Elsevier B.V. All rights reserved.
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| 22. |
- da Cruz Francisco, José, et al.
(författare)
-
Solubility of three monoterpenes, their mixtures and eucalyptus leaf oils in dense carbon dioxide
- 2002
-
Ingår i: Journal of Supercritical Fluids. - 0896-8446. ; 23:1, s. 11-19
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Tidskriftsartikel (refereegranskat)abstract
- The solubility of 1,8-cineole, alpha-pinene, limonene, their mixtures and the extract of eucalyptus leaf oils in supercritical carbon dioxide were determined using the dynamic method at 80, 100, 150, and 250 bar and 40 and 60 degreesC for each pressure. The results showed an increase in the solubility of all oils with an increase in pressure and a decrease with temperature. The mixtures of both pure blends as well as the eucalyptus oil extracts exhibited lower solubility than the pure single oil components in the same conditions. The oil of E. radiata exhibited a better separation of 1,8-cineole at 80 bar and 60 degreesC. (C) 2002 Elsevier Science B.V. All rights reserved.
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| 23. |
- da Cruz Francisco, José, et al.
(författare)
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Supercritical Fluids as Alternative, Safe, Food-Processing Media: An Overview.
- 2003
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Ingår i: Acta Microbiologica Polonica. - 0137-1320. ; 52:Suppl., s. 35-43
-
Tidskriftsartikel (refereegranskat)abstract
- The continuous growth of world population and its concentration in the urban areas require food supplies that are continuous, sufficient and of good quality. To resolve this problem techniques have been developed for increasing food quantity and quality. The techniques are applied throughout the food chain from production, conservation and during distribution to the consumers (from "the field to the fork"). During handling of food, chemicals are often deliberately added to achieve improved processing and better quality. This is one of the main reasons food undergoes different kinds of contamination. This overview focuses on the application of supercritical fluids as media for handling food materials during processing with the perspective of reducing chemical contamination of food. Examples of developmental applications of this technique and on research work in process are presented. Emphasis is given to extraction and biotransformation techniques.
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| 24. |
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| 25. |
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| 26. |
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| 27. |
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| 28. |
- Eriksson, Britas Klemens, 1971-
(författare)
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Long-term changes in macroalgal vegetation on the Swedish coast : An evaluation of eutrophication effects with special emphasis on increased organic sedimentation
- 2002
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In this thesis I examine and evaluate the effects of a documented large-scale eutrophication on macroalgal vegetation on the Swedish coast. During the past century the load of nutrients has increased manifold in the Baltic Sea area, increasing primary production and organic sedimentation significantly. By re-investigating a unique reference material of macroalgal vegetation from the 1940-60s and by conducting new diving studies at the same sites, I showed that long-term trends in macroalgal community composition and species’ distributions are consistent with changes expected from an increased nutrient availability. In the Öregrund archipelago (northern Baltic Sea), I documented a declined depth distribution of the dominant canopy forming alga, Fucus vesiculosus, and an increased abundance of opportunistic ephemeral algae compared to 52-53 years ago. In the Gullmar Fjord area (Skagerrak), trends included increased abundances of functional groups with opportunistic algae, decreased abundances of large perennial algae and a general decline in the depth distribution of the vegetation compared to 36-57 years ago. Sediment removal experiments in the northern Baltic Sea confirmed the hypothesis that sedimentation influences macroalgal community composition. Species depending on short periods of reproduction were clearly favoured by sediment removal, especially F. vesiculosus that seemed limited in depth by the local sediment load. Species with long continuous periods of dispersal by spores and/or fragments (for example the ephemerals Cladophora glomerata, Ceramium tenuicorne and Enteromorpha spp.) were more tolerant to the natural sediment load. In general, sediment removal favoured macroalgal establishment and development, indicating that variation in the natural sediment load is an important constraint for sublittoral rocky-shore macroalgal community development. I conclude by suggesting that the documented long-term changes in macroalgal vegetation on the Swedish coast partly are explained by an increased organic sedimentation in these areas.
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| 29. |
- Espert, Ana, et al.
(författare)
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Comparison of water absorption in natural cellulosic fibres from wood and one-year crops in polypropylene composites and its influence on their mechanical properties
- 2004
-
Ingår i: Composites. Part A, Applied science and manufacturing. - : Elsevier BV. - 1359-835X .- 1878-5840. ; 35:11, s. 1267-1276
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Tidskriftsartikel (refereegranskat)abstract
- Environmentally beneficial composites can be made by replacing glass fibres with various types of cellulose fibres. Fibres from pine or eucalyptus wood and also one-year crops such as coir, sisal, etc. are all good candidates. The poor resistance towards water absorption is one of the drawbacks of natural fibres/polypropylene composites. New natural fibres/polypropylene composites were made and the water absorption in them was studied by immersion of the composites in water at three different temperatures, 23, 50 and 70 degreesC. The process of absorption of water was found to follow the kinetics and mechanisms described by Fick's theory. In addition, the diffusivity coefficient was dependent on the temperature as estimated by means of Arrhenius law. A decrease in tensile properties of the composites was demonstrated, showing a great loss in mechanical properties of the water-saturated samples compared to the dry samples. The morphology change was monitored by scanning electron microscopy studies of the samples before and after exposure to water and the devastating effect of water on the fibre structure was shown.
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| 30. |
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| 31. |
- Francisco, J D, et al.
(författare)
-
Liquid crystalline properties and extractability of monoolein-water systems by supercritical carbon dioxide
- 2003
-
Ingår i: Colloids and Surfaces A: Physicochemical and Engineering Aspects. - 0927-7757. ; 213:1, s. 69-78
-
Tidskriftsartikel (refereegranskat)abstract
- The influence of phase structure on the extraction recovery of monoolein from monoolein-water systems by supercritical carbon dioxide was investigated. Two monoolein-water mi tures at concentrations of 9 wt% water and 18 wt% water, respectively, were studied. H-2-NMR was used to monitor changes of the phase structures in supercritical conditions. The results showed that the phase structure and the water-monoolein interactions play a role on the extraction yield. The monoolein recovery was higher in the 9 wt% water sample in which L-alpha phase was present compared to the 18 wt% water sample in which the L-alpha melted to yield a L-2 phase. When the phase structures were the same in both samples, the extraction recovery was determined by the solubility properties of the components of the system. The changes due to the presence of supercritical carbon dioxide were shown also to depend on the water concentration of the monoolein-water mixture besides the temperature. The 18 wt% mixture showed a L-2 phase structure in all the range of the temperature investigated while the 9 wt% water mixture showed phase changes from L-alpha phase to L-2 phase in the same temperature range. (C) 200 Elsevier Science B.V. All rights reserved.
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| 32. |
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| 33. |
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| 34. |
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| 35. |
- Harzing, Anne-Wil, et al.
(författare)
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The Interaction Between Language and Culture: A Test of the Cultural Accommodation Hypothesis in Seven Countries
- 2002
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Ingår i: Language and Intercultural Communication. - : Informa UK Limited. - 1470-8477 .- 1747-759X. ; 2:2, s. 120-139
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Tidskriftsartikel (refereegranskat)abstract
- We investigate the cultural accommodation hypothesis in questionnaire-based research: Do respondents adjust their responses in a way that reflects the cultural values associated with the language of the questionnaire? A test of this hypothesis with a sample of university students in seven countries indicates that cultural accommodation plays an important role in cross-language research.
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| 36. |
- Hernandez, Francisco, et al.
(författare)
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Accounting for incomplete charge collection in Monte Carlo simulations of the efficiency of well-type Ge-detectors
- 2003
-
Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - 0168-9002 .- 1872-9576. ; 498:1-3, s. 340-351
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Tidskriftsartikel (refereegranskat)abstract
- The influence of the process of incomplete charge collection on the performance properties of HPGe well-type detectors is studied. A simplified sub-routine, that takes into account the total collection time of charges within the Ge-crystal, has been developed and coupled to the Monte Carlo photopeak efficiency. Only the manufacturer's data of the detector's geometry and the detector's operating voltage was used in the sub-routine. The corrected photopeak efficiency simulations, as based on this new sub-routine, showed much better agreement with the experimental data, especially for energies above 40 keV. The ratio between the experimental and simulated efficiency at 1460 keV were, for example, improved from 0.73 to 0.96 after performing these corrections on our largest well-type Ge-detector.
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| 37. |
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| 38. |
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| 39. |
- Hernández Suárez, Francisco Javier, 1973-
(författare)
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Optimisation of environmental gamma spectrometry using Monte Carlo methods
- 2002
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Dissertation in Environmental Physics to be publicly examined in Häggsalen (Ångström Laboratory), Uppsala University, on Friday, November 8, 2002 at 10:00 am for the degree of doctor of philosophy in Physics. The examination will be conducted in English.Gamma spectrometry is one of the tools commonly used for the measurement of various environmental radionuclides. Simultaneous determination of the absolute activity of gamma emitting radiotracers in a wide range of environmental matrices and fractions necessitates proper and accurate evaluation of the sample-to-detector efficiency. Several radiotracers require, in addition, the use of sub-routines for self-absorption corrections.Gamma spectrometry is an important and elegant tool for assessing environmental changes. Optimisation of ultra low-level gamma spectrometry for reliable assessment of such changes requires harmonisation of laboratory needs with sampling and site conditions.Different aspects of the calculation of sample-to-detector efficiencies using empirical and Monte Carlo approaches are discussed here, including the uncertainties related to the simulation of the performance of different HPGe detectors and the effects of the incomplete collection of charges in Ge-crystals. Various simulation codes for the computation of peak efficiencies in planar and well Ge-detectors have been developed from scratch. The results of the simulations have been tested against experimental data and compared to other simulation results obtained with the Monte Carlo N-Particle code (MCNP). The construction of calibration sources with improved absorption and collimation characteristics have been, also, described in this work. These sources have been especially designed for the efficiency calibration of Ge-detectors at energies below 100 keV.Flexible, fully tested and prototype approaches for the evaluation of self-absorption corrections, based on Monte Carlo simulations, are described. Special consideration is given to the problems related to the sample's variability in size, density and composition. Several examples of the absolute and simultaneous determination of environmental multitracers which benefited from self-absorption corrections and the optimised efficiency calibration algorithms are, also, presented and discussed. These examples include, among other things, a comprehensive analysis of the gamma spectrometry of 234Th in a wide range of matrices and the speciation of several radionuclides in sediments from a hard-water lake.
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| 40. |
- Hillier, Ladeana W, et al.
(författare)
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Sequence and comparative analysis of the chicken genome provide unique perspectives on vertebrate evolution
- 2004
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Ingår i: Nature. - 0028-0836 .- 1476-4687. ; 432:7018, s. 695-716
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Tidskriftsartikel (refereegranskat)abstract
- We present here a draft genome sequence of the red jungle fowl, Gallus gallus. Because the chicken is a modern descendant of the dinosaurs and the first non-mammalian amniote to have its genome sequenced, the draft sequence of its genome--composed of approximately one billion base pairs of sequence and an estimated 20,000-23,000 genes--provides a new perspective on vertebrate genome evolution, while also improving the annotation of mammalian genomes. For example, the evolutionary distance between chicken and human provides high specificity in detecting functional elements, both non-coding and coding. Notably, many conserved non-coding sequences are far from genes and cannot be assigned to defined functional classes. In coding regions the evolutionary dynamics of protein domains and orthologous groups illustrate processes that distinguish the lineages leading to birds and mammals. The distinctive properties of avian microchromosomes, together with the inferred patterns of conserved synteny, provide additional insights into vertebrate chromosome architecture.
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| 41. |
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| 42. |
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| 43. |
- Koponen, Eeva, et al.
(författare)
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Effects of linguistic variance on sound-meaning connections in early stages of language acquisition
- 2003
-
Ingår i: Proceedings of the 15th International Congress of Phonetic Sciences. - Adelaide, S. Aust. : Casual Productions. - 1876346493 ; , s. 1975-1978
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Konferensbidrag (refereegranskat)abstract
- To explore the processes underlying early sound-meaning connections an artificial language was created and used in a series of infant speech perception studies. The subjects were tested using the Visual Preference Procedure. The subjects’ responses were quantified in terms of looking times towards objects shown during the audio-visual exposure. Exposure to speech materials with large variance seemed to curtail the subjects’ ability to establish stable sound-meaning connections. However, reducing the linguistic variance led to successful sound-meaning connections. These results indicate that linguistic variance is one of the primary determinants of sound-meaning connections for 1-year old subjects. The paper will discuss how structural differences in natural language settings may account for the infant’s performance on word learning.
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| 44. |
- Koponen, Eeva, et al.
(författare)
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Final lengthening in infant directed speech may function as a cue to phrase constituents
- 2003
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Ingår i: Proceedings from Fonetik 2003, Lövånger, June 2-4, 2003.. - Umeå : Print & Media. - 9173054305 ; , s. 9-12
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The aim of the current study was to investigate whether lengthening of word and phrase final vowels in infant directed speech (IDS) occurs to the same degree as lengthening of word and phrase final vowels in adult directed speech (ADS). The stimuli consisted of vowels embedded in a two-syllable nonsense word that were varied systematically with respect to phrase position and focal accent. At phrase level, the results showed that FL in accented words in IDS was significantly greater as compared to ADS. Earlier studies have shown that young children are sensitive to pauses as markers to phrase constituents. In line with these experiments, the perceptual importance of FL in IDS is discussed.
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| 45. |
- Lacerda, Francisco, 1952-, et al.
(författare)
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Ecological theory of language acquisition
- 2004
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Ingår i: Proceedings of the Fourth International Workshop on Epigenetic RoboticsLund University Cognitive Studies. ; , s. 147-148
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 46. |
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| 47. |
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| 48. |
- Lacerda, Francisco
(författare)
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Phonolgoy: An emergent consequence of memory constraints and sensory input
- 2003
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Ingår i: Reading and Writing: An Interdisciplinary Journal. - 0922-4777 .- 1573-0905. ; 16:1, s. 41-59
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents a theoretical model that attempts to account for the early stages of language acquisition in terms of interaction between biological constraints and input characteristics. The model uses the implications of stochastic representations of the sensory input in a volatile and limited memory. It is argued that phonological structure is a consequence of limited memory resources under the pressure of ecologically relevant multi-sensory information.
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| 49. |
- Lacerda, Francisco, et al.
(författare)
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Preface
- 2001
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Ingår i: Emerging cognitive abilities in early infancy. - Mahwah, NJ, USA : Lawrence Erlbaum Associates. - 0805826696 - 080582670X ; , s. ix-xi
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 50. |
- Lundqvist, Daniel, et al.
(författare)
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The face of wrath : The role of features and configurations in conveying social threat
- 2004
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Ingår i: Cognition & Emotion. - : Informa UK Limited. - 0269-9931 .- 1464-0600. ; 18, s. 161-182
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Tidskriftsartikel (refereegranskat)abstract
- We examined the role of single features and feature configurations in the effect of schematic faces on rated threat. A total of 101 medical students rated their emotional impression of schematic facial stimuli using semantic differential scales (Activity, Negative Valence, and Potency). In different parts of the experiment, the ratings concerned single features, eyebrow‐mouth configurations, or complete faces. Although eyebrows emerged as the overall most important feature, the effect of features was modulated by configuration. Simple configurations of eyebrows and mouth appeared to convey threat and nonthreat in a way highly similar to that of complete faces. In most cases, the configurations of eyebrows and mouth could significantly predict the effect of the complete faces.
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