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31.
Toni Antikainen Olli Paajanen Lauri Rautkari Andreja Kutnar Frederick A. Kamke Mark Hughes 《Wood Science and Technology》2014,48(2):325-336
In this study, birch (Betula pendula L.) veneers were simultaneously densified and dried using a contact drying method at pressures of 1.5 and 3 MPa at 130 °C and compared with veneer dried in a laboratory-scale convective type dryer. Compression rate, thickness swelling, and the density profiles of the veneers were investigated. Furthermore, the microstructure of densified veneers was studied by scanning electron microscopy (SEM). A maximum veneer compression rate of 9 % was achieved at a pressure of 3 MPa. Under these conditions, the veneers were, on average, densified from 504 to 574 kg m?3 (approximately 14 %). After water soaking, full set-recovery—recovery to the initial thickness—occurred. However, the swelling rate was lower for the densified veneer. Density profiles measurements showed that densification occurs throughout the veneers. The SEM images showed that the surface of the densified veneers were smoother, whilst no cracks were detected due to densification. Densification seemed to occur in vessels. Typically, rays were bent when there was a vessel nearby. 相似文献
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Vierimaa O Georgitsi M Lehtonen R Vahteristo P Kokko A Raitila A Tuppurainen K Ebeling TM Salmela PI Paschke R Gündogdu S De Menis E Mäkinen MJ Launonen V Karhu A Aaltonen LA 《Science (New York, N.Y.)》2006,312(5777):1228-1230
Pituitary adenomas are common in the general population, and understanding their molecular basis is of great interest. Combining chip-based technologies with genealogy data, we identified germline mutations in the aryl hydrocarbon receptor interacting protein (AIP) gene in individuals with pituitary adenoma predisposition (PAP). AIP acts in cytoplasmic retention of the latent form of the aryl hydrocarbon receptor and also has other functions. In a population-based series from Northern Finland, two AIP mutations account for 16% of all patients diagnosed with pituitary adenomas secreting growth hormone and for 40% of the subset of patients who were diagnosed when they were younger than 35 years of age. Typically, PAP patients do not display a strong family history of pituitary adenoma; thus, AIP is an example of a low-penetrance tumor susceptibility gene. 相似文献
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Sensitivity of Crops to Increased Ultraviolet Radiation in Northern Growing Conditions 总被引:3,自引:0,他引:3
K. Hakala L. Jauhiainen T. Koskela P. Käyhkö & V. Vorne 《Journal of Agronomy and Crop Science》2002,188(1):8-18
Crops growing at high latitudes are adapted to low intensities of solar ultraviolet B radiation (UV-B). As a result of destruction of stratospheric ozone layer especially at the Polar Regions of the globe, the intensity of UV-B is projected to increase at high latitudes. In order to find out the consequences of increased UV-B on crops, the sensitivity of different varieties of barley, wheat, oats, clover, timothy, meadow fescue, tall fescue and potato was tested in Jokioinen, Finland. The experiment was conducted in the field, under natural light, with a continuous 30 % increase in UV-B. Both increased UV-B and the control with slightly increased UV-A radiation affected the number of lateral shoots in cereals, and the specific leaf area and the content of phenolic substances in grasses. The effects varied according to plant variety and time of growing season. However, no visible damage, nor changes in biomass and yield production were found in any of the crops. Long-term effects on, e.g. genetic stability and germination of crop seed remain to be studied. 相似文献
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Lauri Laakso Ismo K. Koponen Petteri Mönkkönen Markku Kulmala Veli-Matti Kerminen Birgit Wehner Alfred Wiedensohler Zhijun Wu Min Hu 《Water, air, and soil pollution》2006,173(1-4):5-20
In developing countries, aerosol particles damage the health of hundreds of millions of people. Migration from the country side to megacities increases emissions and exposure to particles. Some countries have started to limit emissions based on particulate mass, but this may increase particle number concentrations. In this study we discuss some earlier measurements carried out in the developing world and compare results from one-week measurement campaigns concerning the particle number size distribution and PM10 mass concentrations in New Delhi, India and Beijing, China. Our results show that submicron particle concentrations are high in both places. The average PM10 concentration was 360 μg/m3 in New Delhi and 120 μg/m3 in Beijing. The corresponding total particle number concentrations in the size range 3–800 nm were 63 000 cm?3 and 35 000 cm?3. Number and mass concentrations and their characteristics showed significantly different behaviour between these two locations, which stresses the importance of long-term simultaneous measurements of both quantities in different types of megacities. 相似文献
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Lauri?RautkariEmail author Frederick?A.?Kamke Mark?Hughes 《Wood Science and Technology》2011,45(4):693-705
Density profile relation to hardness of VTC wood composites was evaluated using X-ray densitometry and modified Brinell hardness
method using different applied forces. Moreover, surface elasticity was evaluated. Prior to lamination, the low-density hybrid
poplar (Populus deltoides × Populus trichocarpa L.) and Douglas-fir (Pseudotsuga menziesii L.) thin boards were compressed to 1.22 or 1.14 g/cm3, respectively. Two different kinds of laminations were made, either single layer of 1.5 mm thickness or two 1.5-mm layers
bonded to unmodified wood. The results show that thicker laminate has a great positive influence on Brinell hardness. This
study suggests that results from the existing method for Brinell hardness are not comparable, and if applied force is chosen
without restraint, the effect on the hardness value is significant for inhomogeneous wood composites. 相似文献
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Pirjo Peltonen-Sainio Lauri JauhiainenMika Hyövelä Eero Nissilä 《Field Crops Research》2011,121(2):248-255
Crop-derived feed protein production is alarmingly low in Europe. Finland represents the northernmost growing region in the world and consequently lacks wide-ranging alternatives to improve crop-based protein production. Spring rapeseed, both turnip rape (Brassica rapa L.) and oilseed rape (Brassica napus L.), are adapted to such northern conditions. This study examines the potential for genotype and environment induced trade-off between oil and protein in rapeseed in order to enhance further the status of rapeseed as a protein crop for northern areas. Datasets on advanced breeding progenies (including cultivars) were provided by Boreal Plant Breeding Ltd., while environment-induced variability in combinations of protein and oil content was studied by using long-term, multi-location datasets of MTT Official Variety Trials. Oilseed rape has more potential as a protein producer than turnip rape, with some 100 kg/ha difference in protein yields. Selecting lines superior in seed protein content at the expense of oil was not a potential means to consolidate protein production capacity per hectare: seed and protein yields were higher the better the capacity of the line to store oil. This can only mean that obviously the lower energy demand for oil synthesis was not alternatively used to boost protein production, but actually vice versa. In the case of environment-induced variation, the highest protein yields were produced in experiments where relatively high protein content was associated with modest oil content, but such conditions were characterised as inefficient in general production capacity and thereby, excessive in applied nitrogen fertiliser. Hence, we were not able to identify promising opportunities for prompt and energy-efficient trade-off between protein and oil in rapeseed. 相似文献
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A. I. Nissinen M. Haapalainen L. Jauhiainen M. Lindman M. Pirhonen 《Plant pathology》2014,63(4):812-820
Carrot psyllid Trioza apicalis was recently found to carry the plant pathogenic bacterium ‘Candidatus Liberibacter solanacearum’ (CLs). To confirm the transmission of bacteria by the psyllids and to dissect the symptoms caused in carrot plants by psyllid feeding and CLs infection, a greenhouse experiment with single psyllids feeding on separate plants was performed. A positive correlation was found between the amount of CLs bacteria in the psyllids and in the corresponding plants exposed to feeding, indicating CLs transmission. The female psyllid feeding caused more severe damage than male feeding, and resulted in a substantial decrease in the root weight. Female psyllid feeding also significantly reduced the carrot leaf weight and increased the number of curled leaves. The number of curled leaves was also increased by the nymphs when their number exceeded 10 per plant. A high titre of CLs bacteria significantly reduced root weight, while not affecting the weight or number of the leaves. However, the amount of CLs correlated with the number of leaves showing discolouration symptoms. Microscopy of infected carrot plants revealed that the phloem tubes throughout the whole plant, from leaf veins to the root tip, were colonized by bacteria. The bacterial cells appeared to be long and thin flexible rods with tapering ends and a transversally undulated surface. Microscopy also revealed collapsed phloem cells in the infected carrots. Damage in the phloem vessels is likely to reduce the sucrose transport from source leaves to the root, explaining the observed leaf discolouration and reduction in root weight. 相似文献
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