| 1. |
- Helminen, O, et al.
(författare)
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Predictive value of p53, Ki67 and TLR5 in neoplastic progression of Barrett's esophagus: a matched case-control study
- 2022
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Ingår i: Virchows Archiv : an international journal of pathology. - : Springer Science and Business Media LLC. - 1432-2307. ; 481:3, s. 467-476
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Tidskriftsartikel (refereegranskat)abstract
- Barrett’s esophagus progresses to high-grade dysplasia or cancer along the well-established metaplasia-dysplasia-adenocarcinoma sequence. The aim of this study was to evaluate the value of p53, Ki67, and toll-like receptor 5 (TLR5) in prediction of malignant progression of Barrett’s metaplasia and low-grade dysplasia. This was a retrospective matched case–control study based on Northern and Central Finland population. Patients diagnosed with esophageal high-grade dysplasia or adenocarcinoma were included. From these patients, all previous endoscopy samples were obtained along with original diagnostic HE-slides and clinical data. Age- and sex-matched patients with non-progressing Barrett’s metaplasia and low-grade dysplasia confirmed with follow-up endoscopies were used as controls. Two gastrointestinal pathologist re-reviewed all original HE-slides, and newly made sections to confirm representative tissue material blinded from clinical data. p53, Ki67, and TLR5 were immunohistochemically stained. Final cohort included 45 patients with progressive Barrett’s metaplasia (n = 21) or low-grade dysplasia (n = 24), and 92 patients with non-progressive Barrett’s metaplasia (n = 52) or low-grade dysplasia (n = 40). In Barrett’s metaplasia, aberrant p53 expression was observed in 6% of samples in progressors and 0% in non-progressors. In low-grade dysplasia, aberrant p53 was seen in 56% of samples in progressors and 17% in non-progressors (Odd’s ratio 6.7, 95% CI 1.8–24.6). Ki67 or TLR5 showed no association with disease progression. In this matched case–control study, p53 expression associated with a high risk of malignant progression in Barrett’s low-grade dysplasia. Routine staining of p53 is indicated in expert confirmed low-grade dysplasia.
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| 2. |
- Lemmettylä, T., et al.
(författare)
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The Development and Precision of a Custom-Made Skitester
- 2021
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Ingår i: Frontiers in Mechanical Engineering. - : Frontiers Media SA. - 2297-3079. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- In the sport of cross-country skiing, equipment has a direct influence on results. Ski teams do extensive testing of different ski base grinds and products on a yearly basis. To achieve reliable results, the quality of methods used for testing skis needs to be taken in to account in addition to factors including the physical characteristics of testing personnel and changes in weather conditions. The aim of this study was to introduce a custom-made skitester, that was developed for testing skis on real snow, in laboratory conditions, and to evaluate its precision. The current skitester is capable of glide testing both classic and skate skis as well as kick simulation for the testing of grip waxes. In the present study, glide testing precision was completed in three different conditions. Velocity and pressure of skis were evaluated in three different temperature conditions. During kick simulation, precision was determined in one temperature condition. For glide testing, the precision of the measurement unit was able to distinguish the differences between skis with a relative variation of 0.6–1.1%. However, the track preparation process caused variation. For kick simulation, precision of the measurement unit was slightly higher (2.5%), and track preparation caused less variation. The skitester is capable of distinguishing the differences between both skate and classic cross-country skis with certain limitations.
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| 3. |
- Markkola, A.M., et al.
(författare)
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Estimates of fungal biomass in Scots pine stands on an urban pollution gradient
- 1995
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Ingår i: New Phytologist. - : Wiley. - 0028-646X .- 1469-8137. ; 131:1, s. 139-147
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Tidskriftsartikel (refereegranskat)abstract
- Biomasses of ectomycorrhizal and saprotrophic fungal communities partitioned into sporophores and non‐reproductive structures were estimated in mature Scots pine (Pinus sylvestris L.) stands along an urban nitrogen and sulphur pollution gradient in northern Finland. The average total biomass of fungi varied in the four pollution zones from 14.6 to 20.2 g d. Wt kg−1 soil d. wt and from 73.3 to 108.0 g d. Wt m−2, the mycelia of both mycorrhizai and saprotrophic fungi in the soil comprising 72–80% of the total. The annual carbon allocation to the fungal communities was calculated to vary between 9 and 26% of the estimated annual carbon assimilation at the Scots pine sites. The size of the mean fungal biomass fractions decreased in the following sequence: mycelia in the soil > fungal biomass in fine roots estimated in terms of chitin > sclerotia > fungal biomass in fine roots estimated in terms of ergosterol > sporopbores of mycorrhizal fungi > sporophores of saprotrophie fungi. A positive correlation was obtained between the number of Scots pine mycorrhiza and the average sporophore yield of mvcorrhiaal fungi for three successive years. Tbe sporophore biomass of the mycorrhizal fungi was smaller at the most polluted than at the least polluted sites. The total fungal biomass allocation was not affected by urban pollution.
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| 4. |
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| 5. |
- Ohtonen, O., et al.
(författare)
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EFFECT OF 20 KM SIMULATED RACE LOAD ON PROPULSIVE FORCES DURING SKI SKATING
- 2020
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Ingår i: Karczewska-Lindinger, M., Hakkarainen, A., Linnamo, V., Lindinger, S. (2020) (Eds), Science and Skiing VIII, University of Jyväskylä (publisher), Jyväskylä, Finland, ISBN 978-951-39-8077-1, pp 202. - Jyväskylä, Finland : University of Jyväskylä. - 9789513980771
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Bokkapitel (refereegranskat)
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| 6. |
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| 7. |
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| 8. |
- Pellegrini, B., et al.
(författare)
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Methodological Guidelines Designed to Improve the Quality of Research on Cross-Country Skiing
- 2021
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Ingår i: Journal of Science in Sport and Exercise. - : Springer Science and Business Media LLC. - 2096-6709 .- 2662-1371. ; 3:3, s. 207-223
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Forskningsöversikt (refereegranskat)abstract
- Cross-country (XC) ski races involve a variety of formats, two different techniques and tracks with highly variable topography and environmental conditions. In addition, XC skiing is a major component of both Nordic combined and biathlon competitions. Research in this area, both in the laboratory and field, encounters certain difficulties that may reduce the reliability and validity of the data obtained, as well as complicate comparisons between studies. Here, 13 international experts propose specific guidelines designed to enhance the quality of research and publications on XC skiing, as well as on the biathlon and Nordic combined skiing. We consider biomechanical (kinematic, kinetic and neuromuscular) and physiological methodology (at the systemic and/or muscle level), providing recommendations for standardization/control of the experimental setup. We describe the types of measuring equipment and technology that are most suitable in this context. Moreover, we also deal with certain aspects of nomenclature of the classical and skating sub-techniques. In addition to enhancing the quality of studies on XC skiing, Nordic combined and biathlon, our guidelines should also be of value for sport scientists and coaches in other disciplines where physiological and/or biomechanical measurements are performed in the laboratory and/or outdoors.
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| 9. |
- Stoggl, T., et al.
(författare)
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Comparison of Exclusive Double Poling to Classic Techniques of Cross-country Skiing
- 2019
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Ingår i: Medicine and Science in Sports and Exercise. - : Ovid Technologies (Wolters Kluwer Health). - 0195-9131 .- 1530-0315. ; 51:4, s. 760-772
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Tidskriftsartikel (refereegranskat)abstract
- Introduction This study aimed to 1) determine basic physiological demands during a simulated on-snow cross-country skiing (XCS) race when using grip-waxed skis (all classic XCS techniques [CLASSIC]), versus glide-waxed skis for exclusive double poling (DP) and 2) analyze in which track sections DP is different from CLASSIC under controlled gliding conditions in elite junior and senior skiers. Methods Nineteen male and female elite XC skiers performed 1) two randomized simulated XCS races over 5.3 km using DP or CLASSIC measuring section times, VO2, HR, blood lactate, and RPE; and 2) VO2peak tests using diagonal stride and DP on treadmill. Results The total group showed no differences in performance or physiological responses between DP and CLASSIC. Elite male skiers achieved improved (similar to 23 s, P < 0.05), male juniors equal (P > 0.05) and females worse (similar to 43 s, P < 0.05) performance with DP versus CLASSIC. Flat and undulating terrain favored DP in men, whereas uphill favored CLASSIC in females (similar to 60 s). Uphill sections showed the greatest group differences. Greater RPE was found in the arms during DP, whereas RPE was greater in the legs using CLASSIC. VO2peak in DP was similar to 95% of VO2max. Conclusions Male skiers demonstrated superior performance with exclusively using DP on a Federation International de Ski regulation-compliant XCS track, whereas junior males achieved similar, and females' weaker performance using DP versus CLASSIC. The greatest potential in females is in uphill sections where they distinctly lose time. Exclusive DP might only be beneficial in athletes with high upper-body capacity, and double-pole-specific training and technique. To generalize the findings of the current study, further analysis of snow conditions and course topography is required.
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| 10. |
- Zhao, S., et al.
(författare)
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Contribution and effectiveness of ski and pole forces in selected roller skiing techniques on treadmill at moderate inclines
- 2023
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Ingår i: Frontiers in Sports and Active Living. - : Frontiers Media SA. - 2624-9367. ; 5
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundMost of the studies about the effects of incline on cross-country skiing are related to the metabolic efficiency. The effective skiing biomechanics has also been indicated to be among the key factors that may promote good performance. The aims of this study were to provide biomechanical characteristics and investigate the relative contribution and effectiveness of ski and pole forces in overcoming the total external resistance with double poling (DP) and Gear 3 (G3) techniques at varying moderate uphill inclines.Methods10 male cross-country skiers participated in this study. Custom-made force measurement bindings, pole force sensors, and an 8-camera Vicon system were used to collect force data and ski and pole kinematics at 3 degrees, 4 degrees and 5 degrees with 10 km/h skiing speed.ResultsThe cycle length (CL) decreased by 10% and 7% with DP and G3 technique from 3 degrees to 5 degrees (p < 0.001, p < 0.001). The cycle rate (CR) increased by 13% and 9% from 3 degrees to 5 degrees with DP and G3 technique respectively. From 3 degrees to 5 degrees, the peak pole force increased by 25% (p < 0.001) and 32% (p < 0.001) with DP and G3 technique. With DP technique, the average cycle propulsive force (ACPF) increased by 46% (p < 0.001) from 3 degrees to 5 degrees and with G3 technique, the enhancement for ACPF was 50% (p < 0.001). In G3 technique, around 85% was contributed by poles in each incline.ConclusionThe higher power output in overcoming the total resistance was required to ski at a greater incline. With DP technique, the upper body demands, and technical effectiveness were increasing with incline. With G3 technique, the role of external pole work for propulsion is crucial over different terrains while role of legs may stay more in supporting the body against gravity and repositioning body segments.
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