| 1. |
- Klingberg, G, et al.
(author)
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A survey of specialist paediatric dental services in Sweden: results from 2003, and trends since 1983.
- 2006
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In: International journal of paediatric dentistry / the British Paedodontic Society [and] the International Association of Dentistry for Children. - 0960-7439. ; 16:2, s. 89-94
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Journal article (peer-reviewed)abstract
- The child population in Sweden has changed dramatically during the last 20 years. Changes have also occurred within the Public Dental Service (PDS), regarding the provision of dental care to children and adolescents. All these changes may affect the referral pattern and provision of specialist dental care for children and adolescents. OBJECTIVES: The primary aim of this study was to survey the services provided by specialists in paediatric dentistry in Sweden during 2003. A secondary aim was to compare the results with previous surveys. METHODS: A Web-based survey was sent to all 34 specialist paediatric dentistry clinics and was answered by all clinics. Data were compared with results from the surveys performed in 1983, 1989, and 1996. RESULTS: The number of paediatric dentists had been relatively constant over the last 20 years, whereas the number of children referred to paediatric dentists had increased by 28% since 1983. It was estimated that 1.3% of all children in Sweden are treated at a specialist paediatric dental clinic in 2003. Dental treatment need in combination with behaviour management problems (BMP) was the main reason for referral and occurred in 37% of all referrals. The proportion of medically compromised children/children with disabilities had increased from 6% in 1983 to 22% in 2003. The number of patients treated using sedation and general anaesthesia had increased since 1983, and particularly since 1996. CONCLUSIONS: Despite improvements in dental health among children and adolescents in Sweden during the last 20 years, an increasing number of children are referred for specialist paediatric dental treatment. There is an urgent need to increase the number of specialist paediatric dentists in Sweden in order to ensure the continuation of high quality of dental care for children and adolescents.
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| 2. |
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| 3. |
- Baev, A., et al.
(author)
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A quantum mechanical - Electrodynamical approach to nonlinear properties : Application to optical power limiting with platinum-organic compounds
- 2007
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In: Journal of nonlinear optical physics and materials. - 0218-8635. ; 16:2, s. 157-169
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Journal article (peer-reviewed)abstract
- Light propagation in a medium is sensitively dependent on the shape and intensity of the optical pulse as well as on the electronic and vibrational structure of the basic molecular units. We review in this paper the results of systematic studies of this problem for isotropic media. Our theoretical approach - the quantum mechanical-electrodynamical (QMED) approach - is based on a quantum mechanical account of the many-level electron-nuclear medium coupled to a numerical solution of the density matrix and Maxwell's equations. This allows us to accommodate a variety of nonlinear effects which accomplish the propagation of strong light pulses. Particular attention is paid to the understanding of the role of coherent and sequential excitations of electron-nuclear degrees of freedom. The QMED combination of quantum chemistry with classical pulse propagation enables us to estimate the optical transmission from cross sections of multi-photon absorption processes and from considerations of propagation effects, saturation and pulse effects. Results of the theory suggest that in the nonlinear regime, it is often necessary to simultaneously account for coherent one-step and incoherent step-wise multi-photon absorption, as well as for off-resonant excitations even when resonance conditions prevail. The dynamic theory of nonlinear propagation of a few interacting intense light pulses is highlighted here in a study of the optical power limiting with platinum-organic molecular compounds. © World Scientific Publishing Company.
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| 4. |
- Baev, A., et al.
(author)
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Light-matter interaction of strong laser pulses in the micro-, nano-, and picosecond regimes
- 2007
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In: Materials Research Society Symposium Proceedings. - 9781605604206 ; , s. 12-29
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Conference paper (peer-reviewed)abstract
- Light propagation in a medium is sensitively dependent on the shape and intensity of the optical pulse as well as on the electronic and vibrational structure of the basic molecular units. We review in this paper results of systematic studies of this problem for isotropic media. Our theoretical approach-the quantum mechanical-electrodynamical (QMED) approach-is based on a quantum mechanical account of the many-level electron-nuclear medium coupled to a numerical solution of the density matrix and Maxwell s equations. This allows to accommodate a variety of nonlinear effects which accomplish the propagation of strong light pulses. Particular attention is paid to the understanding of the role of coherent and sequential excitations of electron-nuclear degrees of freedom. The QMED combination of quantum chemistry with classical pulse propagation allows to estimate the optical transmission from cross sections of multi-photon absorption processes and from considerations of propagation effects, saturation and pulse effects. Results of the theory suggest that in the nonlinear regime it is often necessary to account simultaneously for coherent one-step and incoherent step-wise multi-photon absorption, as well as for off-resonant excitations even when resonance conditions prevail. The dynamic theory of nonlinear propagation of a few interacting intense light pulses is here highlighted in a study of the optical power limiting with platinum-organic molecular compounds. © 2007 Materials Research Society.
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| 9. |
- Erlandsson, Martin, et al.
(author)
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Natural variability in lake pH on seasonal, interannual and decadal time scales : implications for assessment of human impact
- 2008
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In: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 42:15, s. 5594-5599
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Journal article (peer-reviewed)abstract
- Reference values define the natural state with respect to environmental stressors and are commonly used for assessments of ecological impacts and to set restoration targets. These reference values are often treated as constants, whereas in reality they can be highly variable. Here, we study the significance of this variability for assessments of human impact on the environment, by using almost two decades of observations from 95 acid-sensitive Swedish lakes. Our approach was to first estimate the preindustrial, steady-state reference level of acid neutralization capacity (ANC) for each lake with the hydro-geochemical model MAGIC. Then the variability in pH around this "baseline" was reconstructed from the contemporary, "natural" variability in the ANC, total organic carbon (TOC) and Al-concentrations, and partial CO2 pressure. The variability in reference pH was then examined for the period 1990-2004, on seasonal (single measurements), interannual (1-year median), and decadal (5-year median) scales. On the seasonal scale, the variability in reference pH ranged between 0.40 and 1.7. The range on the interannual time scale was up to 1.3 units and for the decadal scale up to 0.76 units. Since an anthropogenic pH decline of more than 0.4 units is deemed significant according to the Swedish Environmental Quality Criteria, this natural variability clearly needs to be accounted for when assessing acidification.
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| 10. |
- Erlandsson, Martin, et al.
(author)
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Thirty-five years of synchrony in the organic matter concentrations of Swedish rivers explained by variation in flow and sulphate
- 2008
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In: Global Change Biology. - : Blackwell Publishing. - 1354-1013 .- 1365-2486. ; 14:5, s. 1191-1198
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Journal article (peer-reviewed)abstract
- Increasing concentrations of organic matter ( OM) in surface waters have been noted over large parts of the boreal/nemoral zone in Europe and North America. This has raised questions about the causes and the likelihood of further increases. A number of drivers have been proposed, including temperature, hydrology, as well as SO42 - and Cl (-) deposition. The data reported so far, however, have been insufficient to define the relative importance of different drivers in landscapes where they interact. Thirty-five years of monthly measurements of absorbance and chemical oxygen demand ( COD), two common proxies for OM, from 28 large Scandinavian catchments provide an unprecedented opportunity to resolve the importance of hypothesized drivers. For 21 of the catchments, there are 18 years of total organic carbon (TOC) measurements as well. Despite the heterogeneity of the catchments with regards to climate, size and land use, there is a high degree of synchronicity in OM across the entire region. Rivers go from widespread trends of decreasing OM to increasing trends and back again three times in the 35-year record. This synchronicity in decadal scale oscillations and long-term trends suggest a common set of dominant OM drivers in these landscapes. Here, we use regression models to test the importance of different potential drivers. We show that flow and SO42 - together can predict most of the interannual variability in OM proxies, up to 88% for absorbance, up to 78% for COD. Two other candidate drivers, air temperature and Cl (-) , add little explanatory value. Declines in anthropogenic SO42 - since the mid-1970s are thus related to the observed OM increases in Scandinavia, but, in contrast to many recent studies, flow emerges as an even more important driver of OM variability. Stabilizing SO42 - levels also mean that hydrology is likely to be the major driver of future variability and trends in OM.
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| 12. |
- Islander, Ulrika, 1975, et al.
(author)
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Estren-mediated inhibition of T lymphopoiesis is estrogen receptor-independent whereas its suppression of T cell-mediated inflammation is estrogen receptor-dependent
- 2005
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In: Clin Exp Immunol. - : Oxford University Press (OUP). - 0009-9104 .- 1365-2249. ; 139:2, s. 210-5
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Journal article (peer-reviewed)abstract
- Estrogen has extensive effects on the immune system. The aim of the present experiments was to compare the effects of 17beta-estradiol (E2) and 4-estren-3alpha,17beta-diol (estren) on T lymphopoiesis and T cell-dependent inflammation. In order to investigate the role of estrogen receptors (ER) in the effects of E2 and estren on the immune system, ER knock-out mice lacking both ERalpha and ERbeta (DERKO) were used. T lymphopoiesis and T cell-dependent inflammation were studied by investigating thymus cellularity, the delayed-type hypersensitivity (DTH) reaction, CD4(+) T cells in spleen and serum levels of interleukin (IL)-6. As expected, the presence of ERs was mandatory for all the effects of E2. In contrast, treatment with estren reduced thymus cellularity in ER knock-out mice, indicating an effect through ER-independent pathways. Interestingly, estren suppressed only DTH, the frequency of CD4(+) T cells in spleen and serum levels of IL-6 in wild-type (WT) mice, but not in mice lacking ERs. Thus, our study is the first to show that estren inhibits T lymphopoiesis via ER-independent pathways, whereas its suppressive effects on inflammation are ER-dependent.
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| 13. |
- Islander, Ulrika, 1975, et al.
(author)
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Estren promotes androgen phenotypes in primary lymphoid organs and submandibular glands
- 2005
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In: BMC Immunology. - : Springer Science and Business Media LLC. - 1471-2172. ; 12:6
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Journal article (peer-reviewed)abstract
- BACKGROUND: Estrogens and androgens have extensive effects on the immune system, for example they suppress both T and B lymphopoiesis in thymus and bone marrow. Submandibular glands are sexually dimorphic in rodents, resulting in larger granular convoluted tubules in males compared to females. The aim of the present experiments was to investigate the estrogenic and androgenic effects of 4-estren-3alpha,17beta-diol (estren) on thymus, bone marrow and submandibular glands, and compare the effects to those of 17beta-estradiol (E2) and 5alpha-dihydrotestosterone (DHT), respectively. Estrogen receptors (ERs) were blocked by treatment of mice with the ER-antagonist ICI 182,780; also, knock-out mice lacking one or both ERs were used. RESULTS: As expected, the presence of functional ERs was mandatory for all the effects of E2. Similar to DHT-treatment, estren-treatment resulted in decreased thymus weight, as well as decreased frequency of bone marrow B cells. Treatment with estren or DHT also resulted in a shift in submandibular glands towards an androgen phenotype. All the effects of estren and DHT were independent of ERs. CONCLUSION: Our study is the first to show that estren has similar effects as the androgen DHT on lymphopoiesis in thymus and bone marrow, and on submandibular glands, and that these effects are independent of estrogen receptors. This supports the hypothesis of estren being able to signal through the androgen receptor.
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| 18. |
- Sundberg, Erik, et al.
(author)
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Systemic TNF blockade does not modulate synovial expression of the pro-inflammatory mediator HMGB1 in rheumatoid arthritis patients : a prospective clinical study
- 2008
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In: Arthritis Research & Therapy. - : Springer Science and Business Media LLC. - 1478-6362 .- 1478-6354. ; 10:2, s. R33-
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Journal article (peer-reviewed)abstract
- Introduction High-mobility group box chromosomal protein 1 (HMGB1) has recently been identified as an endogenous mediator of arthritis. TNF and IL-1 beta, pivotal cytokines in arthritis pathogenesis, both have the ability to induce the release of HMGB1 from myeloid and dendritic cells. It was, therefore, decided to investigate whether treatment based on TNF blockade in rheumatoid arthritis (RA) affects the expression of synovial HMGB1. Methods Repeated arthroscopy-guided sampling of synovial tissue was performed in nine patients with RA before and nine weeks after initiation of anti-TNF mAb (infliximab) therapy. Synovial biopsy specimens were analysed for HMGB1 protein by immunohistochemical staining and for HMGB1 mRNA expression by real-time reverse transcriptase PCR (RT-PCR). Statistical evaluations were based on Wilcoxon's signed rank tests or Spearman rank sum tests. Results Aberrant, extranuclear HMGB1 and constitutive nuclear HMGB1 expression, with histological signs of inflammation, were evident in all biopsies obtained before infliximab therapy. Signs of inflammation were still evident in the second biopsies obtained nine weeks after initiation of infliximab therapy. The cytoplasmic and extracellular expression of HMGB1 decreased in five patients, remained unchanged in one patient and increased in three patients, making the overall change in HMGB1 protein expression not significant. No correlation between the clinical response, as measured by disease activity score calculated for 28 joints (DAS28) or the American College of Rheumatology response criteria (ACR 20, 50, and 70), and the direction of change of HMGB1 expression in individual patients could be discerned. In addition, infliximab therapy did not alter HMGB1 mRNA synthesis. Conclusion Pro-inflammatory HMGB1 expression during rheumatoid synovitis was not consistently influenced by TNF-blocking therapy with infliximab. This suggests that TNF is not the main inducer of extranuclear HMGB1 during synovitis and that HMGB1 may represent a TNF-independent molecule that could be considered as a possible target for future therapeutic intervention in RA.
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| 19. |
- Vladimir, E. Kostylev, et al.
(author)
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The relative importance of habitat complexity and surface area in assessing biodiversity: Fractal application on rocky shores
- 2005
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In: Ecological Complexity. - : Elsevier BV. - 1476-945X. ; 2:3, s. 272-286
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Journal article (peer-reviewed)abstract
- Theoretical work predicts that complex habitats allow more species to co-exist in a given area. However, more field studies are still needed to clarify this relationship, especially in intertidal habitats. Furthermore, the potential separate effects of surface complexity and area on species richness and abundance have rarely been addressed. We tested the hypotheses that a more complex substratum or larger surface area will support a greater number of individuals and species of mobile macrofauna on three rocky shores in Hong Kong. Surface complexity, assessed by using fractals, was an important factor in species–area relationships. The number of species increased proportionally to habitat complexity and this relationship was homogeneous among different shores. Total abundance of animals, however, was more dependent on the available surface area. The slope of the size–frequency distribution of animals in samples taken on surfaces with different fractal dimensions (D) was significantly steeper with an increase in fractal dimension, showing that the relative abundance of small animals increased with surface complexity. Thus, surface complexity and area may be important in determining different aspects of the macrofaunal community structure on rocky shores. The resulting increase in surface area on more rough surfaces may introduce bias in density and species number assessments when two-dimensional sampling units (i.e., quadrats) are employed. It is necessary, therefore, to account for the surface complexity in the design and interpretation of the results of benthic studies. Using D as an index of surface complexity is very useful, but also involves some practical problems, e.g., surfaces may be anisotropic and different methods may give different estimates of D. Therefore, these different methods need to be calibrated before comparisons of D values between them are meaningful.
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| 20. |
- Widen, Stephen E., 1975-, et al.
(author)
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Hearing, use of hearing protection, and attitudes towards noise among young American adults
- 2009
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In: International Journal of Audiology. - : Informa UK Limited. - 1499-2027 .- 1708-8186. ; 48:8, s. 537-545
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Journal article (other academic/artistic)abstract
- The purpose of the present study was to investigate possible associations between college students' attitudes, risk-taking behaviour related to noisy activities, and hearing problems such as threshold shifts or self-experienced hearing symptoms. The sample included 258 students aged between 17 and 21 enrolled at the University of Pennsylvania, USA. A questionnaire measuring attitudes towards noise, use of hearing protection, and self-reported hearing symptoms was distributed among the students. After completing the questionnaire a hearing screening, including pure-tone audiometry and tympanometry, was conducted. The result revealed that 26% had thresholds poorer than the screening level of 20 dBHL. Attitudes were significantly related to self-experienced hearing symptoms, but not to threshold shifts. Attitudes and noise sensitivity was, significantly related to use of hearing protection. Hearing protection use was found in activities such as using firearms, mowing lawns, and when using noisy tools but was less reported for concerts and discotheques. It can be concluded that the young adults in this study expose themselves to hearing risks, since the use of hearing protection is in general very low. © 2009 Informa UK Ltd All rights reserved.
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| 21. |
- Widén, Stephen, 1975, et al.
(author)
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Hearing, hearing-related risk-taking behaviour and attitudes towards noise among young American adults
- 2009
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In: International Journal of audiology. ; 48:537-545
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Journal article (peer-reviewed)abstract
- The purpose of the present study was to investigate possible associations between college students’ attitudes, risk-taking behaviour related to noisy activities, and hearing problems such as threshold shifts or self-experienced hearing symptoms. The sample included 258 students aged between 17 and 21 enrolled at the University of Pennsylvania, USA. A questionnaire measuring attitudes towards noise, use of hearing protection, and selfreported hearing symptoms was distributed among the students. After completing the questionnaire a hearing screening, including pure-tone audiometry and tympanometry, was conducted. The result revealed that 26% had thresholds poorer than the screening level of 20 dBHL. Attitudes were significantly related to self-experienced hearing symptoms, but not to threshold shifts. Attitudes and noise sensitivity was, significantly related to use of hearing protection. Hearing protection use was found in activities such as using firearms, mowing lawns, and when using noisy tools but was less reported for concerts and discotheques. It can be concluded that the young adults in this study expose themselves to hearing risks, since the use of hearing protection is in general very low.
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