| 1. |
- Halme, P., et al.
(författare)
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Challenges of ecological restoration : Lessons from forests in northern Europe
- 2013
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Ingår i: Biological Conservation. - : Elsevier BV. - 0006-3207 .- 1873-2917. ; 167, s. 248-256
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Forskningsöversikt (refereegranskat)abstract
- The alarming rate of ecosystem degradation has raised the need for ecological restoration throughout different biomes and continents. North European forests may appear as one of the least vulnerable ecosystems from a global perspective, since forest cover is not rapidly decreasing and many ecosystem services remain at high level. However, extensive areas of northern forests are heavily exploited and have lost a major part of their biodiversity value. There is a strong requirement to restore these areas towards a more natural condition in order to meet the targets of the Convention on Biological Diversity. Several northern countries are now taking up this challenge by restoring forest biodiversity with increasing intensity. The ecology and biodiversity of boreal forests are relatively well understood making them a good model for restoration activities in many other forest ecosystems. Here we introduce northern forests as an ecosystem, discuss the historical and recent human impact and provide a brief status report on the ecological restoration projects and research already conducted there. Based on this discussion, we argue that before any restoration actions commence, the ecology of the target ecosystem should be established with the need for restoration carefully assessed and the outcome properly monitored. Finally, we identify the most important challenges that need to be solved in order to carry out efficient restoration with powerful and long-term positive impacts on biodiversity: coping with unpredictability, maintaining connectivity in time and space, assessment of functionality, management of conflicting interests and social restrictions and ensuring adequate funding. © 2013 Elsevier Ltd.
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| 2. |
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| 3. |
- Janhunen, P., et al.
(författare)
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Invited Article: Electric solar wind sail : Toward test missions
- 2010
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Ingår i: Review of Scientific Instruments. - : AIP Publishing. - 0034-6748 .- 1089-7623. ; 81:11, s. 111301-
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Tidskriftsartikel (refereegranskat)abstract
- The electric solar wind sail (E-sail) is a space propulsion concept that uses the natural solar wind dynamic pressure for producing spacecraft thrust. In its baseline form, the E-sail consists of a number of long, thin, conducting, and centrifugally stretched tethers, which are kept in a high positive potential by an onboard electron gun. The concept gains its efficiency from the fact that the effective sail area, i.e., the potential structure of the tethers, can be millions of times larger than the physical area of the thin tethers wires, which offsets the fact that the dynamic pressure of the solar wind is very weak. Indeed, according to the most recent published estimates, an E-sail of 1 N thrust and 100 kg mass could be built in the rather near future, providing a revolutionary level of propulsive performance (specific acceleration) for travel in the solar system. Here we give a review of the ongoing technical development work of the E-sail, covering tether construction, overall mechanical design alternatives, guidance and navigation strategies, and dynamical and orbital simulations.
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| 4. |
- Penttilä, S., et al.
(författare)
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Late-onset spinal motor neuronopathy - A common form of dominant SMA
- 2014
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Ingår i: Neuromuscular Disorders. - : Elsevier BV. - 0960-8966. ; 24:3, s. 259-268
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Tidskriftsartikel (refereegranskat)abstract
- We previously described two Finnish families with a new autosomal dominant late-onset spinal motor neuronopathy that was mapped to chromosome 22q11.2-q13.2. In the current screening study of 43 lower motor neuron disease patients from Finland and Sweden, we identified 26 new late-onset spinal motor neuronopathy patients sharing the founder haplotype. In addition to the main symptoms and signs: painful cramps, fasciculations, areflexia and slowly evolving muscle weakness, new features such as mild bulbar findings, were identified. The disease is relatively benign in terms of life expectancy and rate of disability progression, and it is therefore noteworthy that three patients were initially misdiagnosed with ALS. Significant recombinants in this new patient cohort restricted the disease locus by 90% to 1.8. Mb. Late-onset spinal motor neuronopathy seems not to be very rare, at least not in Finland, with 38 patients identified in a preliminary ascertainment. © 2013 Elsevier B.V.
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| 6. |
- Azremi, A.A.H., et al.
(författare)
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On diversity performance of two-element coupling element based antenna structure for mobile terminal
- 2010
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Ingår i: EuCAP 2010 Fourth European Conference on Antennas and Propagation, Barcelona, 12-16 April 2010.
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Konferensbidrag (refereegranskat)abstract
- In wireless communication systems, multipath interference has a significant impact on system design and performance. Fast fading is caused by the coherent summation of one or more echoes from many reflection points reaching the receive antenna. Antenna diversity can be used to mitigate multipath fading. The main challenge of antenna diversity in practical application is the integration of multiple antennas on a small ground plane. Two-element antenna structure based on coupling element antenna concept for diversity application has been studied in previous work and it has shown to be feasible for low frequency diversity application with stable and low envelope correlation across wide frequency range. The studied structure has been tuned to be operating at 1600 MHz for measurement evaluation purpose. This paper presents an analysis of diversity performance of the structure in terms of efficiencies, envelope correlation, and apparent and effective diversity gains in isotropic (i.e. statistically uniform) propagation channel, using spherical near-field technique in an ideal line-of-sight environment (anechoic chamber) and inside reverberation chamber. The envelope correlation is less than 0.1 and the diversity gain is equal to 10.2 dB at 99% reliability level using selection combining technique across simulation and both measurement methods. The measurement techniques are compared to show how accurately the diversity performance of a mobile terminal antenna can be estimated.
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| 7. |
- Griep Härter, Rosane, et al.
(författare)
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Years worked at night and body mass index among registered nurses from eighteen public hospitals in Rio de Janeiro, Brazil
- 2014
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Ingår i: BMC Health Services Research. - : Springer Science and Business Media LLC. - 1472-6963. ; 14
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Employees working night shifts are at a greater risk of being overweight or obese. Few studies on obesity and weight gain analyze the years of exposure to night work. The aim of this study was to determine the relationship between the years of exposure to night work and body mass index (BMI) among registered nurses.METHODS: A cross-sectional analysis was performed in 18 largest public hospitals in Rio de Janeiro, Brazil. A total of 2,372 registered nurses (2,100 women) completed a comprehensive questionnaire concerning sociodemographic, professional, lifestyle, and health behavioral data. Current and past exposures to night shifts as well as BMI values were measured as continuous variables. A gamma regression model was used with an identity link function to establish the association.RESULTS: The association between years of exposure to night work and BMI was statistically significant for both women and men after adjusting for all covariates [β = 0.036; CI95% = 0.009-0.063) and β = 0.071 (CI95% = 0.012-0.129), respectively]. The effect of night work was greater among men than women. For example, for those women who have worked at night for 20 years the estimated average BMI was 25.6 kg/m2 [range, 25.0-26.2]. In relation to men, after 20 years of exposure to night work the estimated average BMI was 26.9 kg/m2 [range, 25.6-28.1].CONCLUSIONS: These findings suggest that night shift exposure is related to BMI increases. Obesity prevention strategies should incorporate improvements in work environments, such as the provision of proper meals to night workers, in addition to educational programs on the health effects of night work.
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