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21.
Peltonen H Arokoski J Kallinen M Pullinen T 《Journal of electromyography and kinesiology》2012,22(3):424-430
BackgroundThe aim of the study was to evaluate differences in the loading of glenohumeral joint muscles between a cable pulley machine (CP) and variable resistance machine (VR) during axial humeral external rotation.MethodsEleven healthy male subjects took part in the study. Intramuscular electromyography from five muscles of the shoulder (medial deltoid, supraspinatus, infraspinatus and upper part of the trapezius), torque and power output was measured at different rotation angles and with different loads (10%, 50% and 100% of 1RM). Also the compressive and shear force in the glenohumeral joint was analyzed at the horizontal level at angles of rotation. External rotation was performed with a self-selected velocity on the scapular plane.FindingsIn the CP the range of movement became narrower than in the VR with increasing workload (P < 0.05). The activity of the infraspinatus did not grow in the CP after 50% load, while it did in the VR (P < 0.01). The upper part of the trapezius was activated less in the CP than in the VR (P < 0.01) machine when using 50% and 100% loads. In comparison with the CP, the shear forces that pull the head of the humerus in a posterior direction were more evenly distributed in the VR than in the CP at different angles of rotation (P < 0.001).InterpretationThe VR seems to make a broader range of motion possible, lager activation the primary external rotators and evenly distributed shear forces than the CP. However, performing the exercise with VR and high load also activates the upper part of the trapezius.RelevanceThese findings can be used in the development of exercise designs, methods and equipment for shoulder injury rehabilitation. 相似文献
22.
23.
Paavo Ahvenniemi Matthias Wolf Mari J. Lehtonen Paula Wilson Malgorzata German-Kinnari Jari P. T. Valkonen 《Journal of molecular evolution》2009,69(2):150-163
The rRNA cistron (18S–ITS1–5.8S–ITS2–28S) is used widely for phylogenetic analyses. Recent studies show that compensatory
base changes (CBC) in the secondary structure of ITS2 correlate with genetic incompatibility between organisms. Rhizoctonia solani consists of genetically incompatible strain groups (anastomosis groups, AG) distinguished by lack of anastomosis between
hyphae of strains. Phylogenetic analysis of internal transcribed spacer (ITS) sequences shows a strong correlation with AG
determination. In this study, ITS sequences were reannotated according to the flanking 5.8S and 28S regions which interact
during ribogenesis. One or two CBCs were detected between the ITS2 secondary structure of AG-3 potato strains as compared
to AG-3 tobacco strains, and between these two strains and all other AGs. When a binucleate Rhizoctonia species related to Ceratobasidiaceae was compared to the AGs of R. solani, which were multinucleate (3–21 nuclei per cell), 1–3 CBCs were detected. The CBCs in potato strains of AG-3 distinguish
them from AG-3 tobacco strains and other AGs yielding further evidence that the potato strains of AG-3 originally described
as R. solani are a species distinct from other AGs. The ITS1–5.8S–ITS2 sequences were analyzed by direct sequencing of PCR products from
497 strains of AG-3 isolated from potato. The same 10 and 4 positions in ITS1 and ITS2, respectively, contained variability
in 425 strains (86%). Nine different unambiguous ITS sequences (haplotypes) could be detected in a single strain by sequencing
cloned PCR products indicating that concerted evolution had not homogenized the rRNA cistrons in many AG-3 strains. Importantly,
the sequence variability did not affect the secondary structure of ITS2 and CBCs in AG-3.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
24.
BACKGROUND AND AIMS: Changes in number of trichomes and in composition and concentrations of their exudates throughout leaf development may have important consequences for plant adaptation to abiotic and biotic factors. In the present study, seasonal changes in leaf trichomes and epicuticular flavonoid aglycones in three Finnish birch taxa (Betula pendula, B. pubescens ssp. pubescens, and B. pubescens ssp. czerepanovii) were followed. METHODS: Trichome number and ultrastructure were studied by means of light, scanning and transmission electron microscopy, while flavonoid aglycones in ethanolic leaf surface extracts were analysed by high-pressure liquid chromatography. KEY RESULTS: Density of both glandular and non-glandular trichomes decreased drastically with leaf expansion while the total number of trichomes per leaf remained constant, indicating that the final number of trichomes is established early in leaf development. Cells of glandular trichomes differentiate before those of the epidermis and produce secreted material only during the relatively short period (around 1-2 weeks) of leaf unfolding and expansion. In fully expanded leaves, glandular trichomes appeared to be at the post-secretory phase and function mainly as storage organs; they contained lipid droplets and osmiophilic material (probably phenolics). Concentrations (mg g(-1) d. wt) of surface flavonoids decreased with leaf age in all taxa. However, the changes in total amount ( microg per leaf) of flavonoids during leaf development were taxon-specific: no changes in B. pubescens ssp. czerepanovii, increase in B. pendula and in B. pubescens ssp. pubescens followed by the decline in the latter taxon. Concentrations of most of the individual leaf surface flavonoids correlated positively with the density of glandular trichomes within species, suggesting the participation of glandular trichomes in production of surface flavonoids. CONCLUSIONS: Rapid decline in the density of leaf trichomes and in the concentrations of flavonoid aglycones with leaf age suggests that the functional role of trichomes is likely to be most important at the early stages of birch leaf development. 相似文献
25.
Carbohydrates present on cell surfaces participate in numerous biological recognition phenomena including cell–cell interactions,
cancer metastasis and pathogen invasion. Therefore, synthetic carbohydrates have a potential to act as pharmaceutical substances
for treatment of various pathological phenomena by inhibiting specifically the interaction between cell surface carbohydrates
and their protein receptors (lectins). However, the inherently low affinity of carbohydrate-protein interactions has often
been an obstacle for successful generation of carbohydrate based pharmaceuticals. Multivalent glycoconjugates, i.e. structures
carrying several copies of the active carbohydrate sequence in a carrier molecule, have been constructed to overcome this
problem. Here we present two novel types of multivalent carbohydrate conjugates based on chondroitin oligomer and cyclodextrin
carriers. These carriers were modified to express primary amino groups, and oligosaccharides were then bound to carrier molecules
by reductive amination. Multivalent conjugates were produced using the human milk type oligosaccharides LNDFH I (Lewis-b hexasaccharide),
LNnT, and GlcNAcβ1-3Galβ1-4GlcNAcβ1-3Galβ1-4Glc. 相似文献
26.
Using the ecosystem services approach for better planning and conservation of urban green spaces: a Finland case study 总被引:6,自引:0,他引:6
Jari Niemelä Sanna-Riikka Saarela Tarja Söderman Leena Kopperoinen Vesa Yli-Pelkonen Seija Väre D. Johan Kotze 《Biodiversity and Conservation》2010,19(11):3225-3243
Ecosystem services are vital for humans in urban regions. However, urban development poses a great risk for the ability of
ecosystems to provide these services. In this paper we first address the most important ecosystem services in functional urban
regions in Finland. Well accessible and good quality recreational ecosystem services, for example, provided by urban nature,
are an important part of a high-quality living environment and important for public health. Vegetation of urban regions can
have a role in carbon dioxide sequestration and thus in climate change mitigation. For instance, estimates of carbon sinks
can be compared to total CO2 emissions of an urban region, and the municipality can aim at both increasing carbon sinks and decreasing CO2 emissions with proper land-use planning. Large and contiguous core nature areas, smaller green areas and ecological connections
between them are the essence of regional ecological networks and are essential for maintaining interconnected habitats for
species and thus biological diversity. Thus, both local and regional level ecological networks are vital for maintaining ecosystem
services in urban regions. The impacts of climate change coupled with land-use and land cover change will bring serious challenges
for maintaining ecosystem services in urban areas. Although not yet widely used in planning practices, the ecosystem services
approach can provide an opportunity for land-use planning to develop ecologically sustainable urban regions. Currently, information
on ecosystem services of urban regions is lacking and there is a need to improve the knowledge base for land-use planning. 相似文献
27.
Mäkinen TM Raatikka VP Rytkönen M Jokelainen J Rintamäki H Ruuhela R Näyhä S Hassi J 《International journal of biometeorology》2006,51(1):27-36
The extent of outdoor exposure during winter and factors affecting it were examined in a cross-sectional population study in Finland. Men and women aged 25–74 years from the National FINRISK 2002 sub-study (n=6,591) were queried about their average weekly occupational, leisure-time and total cold exposure during the past winter. The effects of gender, age, area of residence, occupation, ambient temperature, self-rated health, physical activity and education on cold exposure were analysed. The self-reported median total cold exposure time was 7 h/week (8 h men, 6 h women),<1 h/week (2 h men, 0 h women) at work, 4 h/week (5 h men, 4 h women) during leisure time and 1 h/week (1 h men, 1.5 h women) while commuting to work. Factors associated with increased occupational cold exposure among men were: being employed in agriculture, forestry and industry/mining/construction or related occupations, being less educated and being aged 55–64 years. Factors associated with increased leisure-time cold exposure among men were: employment in industry/mining/construction or related occupations, being a pensioner or unemployed, reporting at least average health, being physically active and having college or vocational education. Among women, being a housewife, pensioner or unemployed and engaged in physical activity increased leisure-time cold exposure, and young women were more exposed than older ones. Self-rated health was positively associated with leisure time cold exposure in men and only to a minor extent in women. In conclusion, the subjects reported spending 4% of their total time under cold exposure, most of it (71%) during leisure time. Both occupational and leisure-time cold exposure is greater among men than women. 相似文献
28.
Fluxes of nitrous oxide and methane from drained peatlands following forest clear-felling in southern Finland 总被引:2,自引:1,他引:2
Jari T. Huttunen Hannu Nykänen Pertti J. Martikainen Mika Nieminen 《Plant and Soil》2003,255(2):457-462
Drainage of waterlogged sites has been part of the normal forestry practice in Fennoscandia, the Baltic countries, the British Isles and in some parts of Russia since the early 20th century, and currently, about 15 million hectares of peatlands and other wetlands have been drained for forestry purposes. The rate of forest clear-felling on drained peatlands will undergo a rapid increase in the near future, when a large number of these forests approach their regeneration age. A small-scale pilot survey was performed at two nutrient-rich and old peatland drainage areas in southern Finland to study if forest clear-felling has significant impacts on the exchange of nitrous oxide (N2O) and methane (CH4) between soil and atmosphere. The average N2O emissions from the two drainage areas during three growing seasons following clear-felling were 945 and 246 g m–2 d–1. The corresponding CH4 fluxes were –0.07 and –0.52 mg m–2 d–1. Clear-felling had impacts on the environmental factors known to affect the N2O and CH4 fluxes of peatlands, i.e. clear-felling raised the water table level and increased the peat temperature. However, no substantial changes in the fluxes of CH4 following clear-felling were observed. The results concerning N2O indicated a potential for increased emissions following clear-felling of drained peatland forests, but further studies are needed for a critical evaluation of the impacts of clear-felling on the fluxes of CH4 and N2O. 相似文献
29.
Effects of a hydropower plant on Coleopteran diversity and abundance in the Udzungwa Mountains, Tanzania 总被引:2,自引:2,他引:0
Innocent J.E. Zilihona Jari Niemelä Matti Nummelin 《Biodiversity and Conservation》2004,13(8):1453-1464
The effects of river flow diversion on biodiversity were assessed using Coleoptera as an indicator group in three habitats of the Kihansi Gorge (Udzungwa Mountains, Tanzania), before and after commissioning of a hydropower plant. Data collected using sweep netting and pitfall traps showed that the effect of diversion of the river flow was site-specific, affecting particularly the spray habitat. Rarefaction analysis of both sweep netting and pitfall samples indicated that the expected richness of Coleoptera declined significantly in all habitats after commissioning of the power plant. Sweep netting and pitfall samples showed that the highest Shannon–Wiener diversity index value before the diversion of the river flow was in the spray zone, but the index value decreased after diversion. Changes in the other two habitats were less prominent. Analysis of variance using diversity index values from five pitfall samples in each habitat type before and after commissioning indicated that there were no statistically significant differences in the diversity index between the two sampling periods or among the three habitat types. Renkonen's similarity index between habitats showed that pitfall samples had higher similarity (87%) than did samples from sweep netting (69%). It is suggested that for mitigation purposes, artificial spray systems, which have been installed in other wetlands of the Kihansi Gorge, also be installed to cover the whole Lower Wetland in which this study was undertaken. In order to maintain overall biodiversity in the Kihansi Gorge, it is suggested that the ecosystem conservation approach be prioritised. 相似文献
30.
Up to four tetra-tert-butyl-1-[4-aminoacetamido)benzyl]diethylenetriaminetetrakis(acetato) derivatives of Fmoc glutamic acid (1) were attached to two steroids (17alpha-hydroxyprogesterone-3-O-carboxymethyloxime 2 and 1,3,5(10)-estratriene-3,16alpha,17beta-triol-6-one-6-O-carboxymethyloxime, 3)) on solid phase using an oligopeptide synthesizer. Upon deprotection and conversion to the corresponding europium(III) chelates, these steroid conjugates were used in DELFIA-based competitive fluoroimmunoassays. The more chelates conjugated to 17-alpha-hydroxyprogesterone, the more diluted antiserum could be used in an immunoassay for 17-alpha-hydroxyprogesterone, without any alteration of the measurement range. Hence, 17-alpha-hydroxyprogesterone tracers with several chelates are useful when a high serum dilution factor is desired i.e., when only a limited quantity of antiserum is available. The result demonstrates the suitability and usefulness of lanthanide(III) chelates as multilabels in bioaffinity assays. 相似文献